LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

Class 


Millwrighting 


By 

James  F.  Hobart 


1909 

HILL   PUBLISHING   COMPANY 

505   Pearl  Street,  New  York 
6  Bouverie  Street,  London,  E.  C. 


AMERICAN  MACHINIST -POWER— THE  ENGINEERING  AND  MINING  JOURNAL 


^ 


Copyright,  1909,  by  the  Hill  Publishing  Company 


6ENEBAL 


Hill  Publishing  Company,  New  York,  U.  S.  A. 


INTRODUCTION. 

The  purpose  of  this  book  is  to  enable  you  as  a  millwright  to 
begin  your  work  where  others  left  off.  It  is  my  desire  to  save 
you  the  necessity  of  going  over  the  ground  traveled  by  others 
in  your  chosen  field.  The  results  of  my  experience,  observation 
and  study  are  set  forth  in  this  book  together  with  the  best  prac- 
tice of  other  millwrights  in  the  hope  that  you  may  be  able  to 
avail  yourself  of  my  efforts  and  increase  your  value  to  your 
employer  and  your  ability  to  command  a  higher  salary. 

JAMES  F.  HOBART. 
Detroit,  Mich.,  Nov.  18,  1908. 


190794 


CONTENTS 

CHAPTER  I. 

The  Millwright  and  What  He  is  —  Qualifications  of  a  Millwright  — 
Study  Methods  —  Steel  and  Timber  Framing. 

CHAPTER  II. 

Factory  Location  —  Movement  of  Material  During  Manufacture  — 
Sawmill  Arrangement — Lack  of  Working  Space  Around  Machines. 

CHAPTER  III. 

Laying  out  The  Buildings  —  Methods  of  Laying  Out  Foundations  — 
The  Builder's  Level  —  Center  or  Base  Lines  —  Laying  out  Foundations 
with  the  Transit  —  Secondary  Lines  —  Permanent  Stations  or  Targets  — 
Station  Points  and  Stones — Arrangement  of  Stations  and  Sub-Stations — 
A  Station-Rod  —  Using  the  Station-Rod  —  Long  and  Short  Station-Rods 

—  Laying  Down  Cross-Lines  —  Advantages  of  The  Station-Rod  Method. 

CHAPTER  IV. 

The  Builder's  Level  and  Foundations  —  Cost  of  Stone  Stations  —  Con- 
crete Station  Stones  —  The  Determination  of  Foundation  Levels  —  Home- 
Made  Leveling-Rod  or  Staff  —  Vernier  Scale-Making  and  Reading  —  Use 
of  the  Leveling-Rod  —  Leveling  Foundations  with  a  Cross-Hair  Instru- 
ment—Plumbing the  Leveling-Rod  —  Batter  Boards  —  Locating  and 
Erecting  Batter-Boards  —  Batter-Boards  Erected  to  Grade  —  Locating  and 
Fastening  Chalk  Lines  —  Saw-Cuts  in  Batter-Boards  —  Putting  up  Batter- 
Boards  —  Reading  the  Leveling-Rod  —  Running  Long  Levels  —  Curvature 
of  the  Earth  —  Causes  of  Error  in  Leveling. 

CHAPTER  V. 

Foundations  and  the  Carpenter's  Level  —  Running  Levels  with  the 
Straight-Edge  and  Carpenter's  Level  —  Leveling  a  Line  of  Stakes  —  Mark- 
ing Batter- Posts  —  The  Rudimentary  Plane  Table  —  Sighting  over  the 
Carpenter's  Level  —  Operating  a  Plane-Table  —  Using  the  Plane-Table 
and  a  Carpenter's  Level  —  Setting  Batter-Boards  and  Stakes  —  Accurate 
Sighting  over  a  Level  —  Sighting  Strips  Arranged  on  Level  —  "Gun-Com- 
pass" Level  Sights  —  Level  Arranged  with  "Gun-Compass"  Sights  — 
Adjusting  Sights  on  a  Carpenter's  Level — Home-Made  Leveling  Telescope 

—  Carpenter's  Level  Arranged  with  Telescope  Sights  and  Cross-Hairs  — 
Focal  Distance  of  Lenses  —  Mounting  Lenses  in  a  Tube  —  A  Spectacle- 
Pipe  Telescope  —  Mounting  and   Adjusting   Cross-Hairs  —  Focusing  —  A 
Rifle  Telescope  —  Use  of  Tape-Line  and  Pole  —  "Squaring"  a  Line  —  The 
Six,  Eight  and  Ten  Method  of  Squaring  a  Line  —  New  Method  of  Squar- 
ing a  Line  —  The  Radius  Board  —  Radius  Board  for  Laying  off  a  Right- 
Angle  —  Squaring  a  Line  with  the  Radius  Board  —  Principle  of  the  Radius 
Board  —  Leveling  Long  and  Short  Lines. 


2  CONTENTS 

CHAPTER  VI. 

Erecting  Building  and  Machinery  Foundations  —  Wasteful  Foundation 
Drawings  —  Lead-Carrying  Power  of  Different  Soils  — Table  of  Bearing 
Power  of  Soils  — Shape  of  Concrete  Foundations  —  Costly  Taper-Side 
Foundations  —  Costly  and  Troublesome  Form  —  Troublesome  Foundation 
Re-designed  — Testing  Carrying  Power  of  Soils —  Taper-Side  Foundation 
Re-designed  —  Cheaply  Constructed  Form  —  Cheap  Form  for  Re-designed 
Pier  —  Vigilance  Necessary  by  the  Millwright — Concrete  Construction  — 
Reinforced  Concrete  —  Scientific  Method  of  Proportioning  Concrete  — 
Curves  for  Proportioning  Concrete  —  Laying  a  Concrete  Curve  —  Sieve 
or  Screen  Sizes  and  Numbers  — To  Determine  the  Necessary  Quantity  of 
Sand  for  Concrete— Proportions  of  Sand  and  Cement  for  various  sizes 
of  Stone  —  Concrete  with  Fine  Stone  or  Gravel  —  Lime  in  Cement  Mortar 

—  Hydrated   Lime   and   L;  le   Mortar  —  Slacking  or    Hydrating  Lime  — 
Recrystalization  and  "Burning"  Lime. 

CHAPTER  VII. 

.  Erection  of  Buildings  —  Masonry  Construction  —  Laying  Brick  —  Con- 
crete Construction  —  Making  and  Placing  Forms  —  Strength  of  Wooden 
Forms  —  Time  to  Remove  Forms  —  Reinforced  Concrete  —  Calculating  a 
Machinery  Pier  of  Reinforced  Concrete  —  Calculating  a  Reinforced  Con- 
crete Footing  —  The  Ransome  System  of  Concrete  Constructon  —  Rule  for 
Pier  Footings  —  Table  of  Ransome  Bars,  Weight,  Size  and  Strength  — 
Solving  the  Footing  Problem  by  Algebra  —  Calculating  a  Pier  Footing 
by  Algebra  —  Offsets  for  Solid  Masonry  Footings  —  Table  of  Safe  Loads 
for  Masonry  Footing  Courses  —  Inspection  During  Erection  —  Holding  the 
Contractor  to  Specifications  —  The  Give  and  Take  Method  of  Inspecting 

—  Inspecting   for  Graft  —  Wooden  Factory   Construction  —  Frame   Struc- 
tures—  Old-Time   Frame   Construction  —  Some  Old-Time    Framing  —  Siz- 
ing   Timber  —  Balloon    Framing — Shafting    Hung    to    Balloon    Frame  — 
Slow-Burning  Mill  Construction — Framing  on  the  Job  and  at  the  Mill  — 
Economy  of  Material  —  Lumber-Inspection  —  Laying  out  Framing  —  Lay- 
ing out  Framing  with  the  Steel  Square  —  The  Laying-Out  Gage  —  Using 
the    Laying-Out    Gage  —  Marking   "Daps"    with   the    Laying-Out    Gage  — 
Marking  Draw-Bores  with  a   Steel  Square  —  Universal  Laying-Out  Gage 

—  Working  from  "the  Face  Corner"  —  Squaring  around  a  Timber  —  Tak- 
ing Timber  out  of  Wind  —  Sighting  and  Spotting  Timber  out  of  Wind  — 
Boxing,  or  Cutting  "Daps" — Dapping,  or  Boxing  Tool. 

CHAPTER  VIII. 

Walls  and  Machinery  Supports  —  Drop  Hangers  vs.  Pillow  Blocks  — 
Shafting  on  Bin-Supports  —  Walls  for  Supporting  Shafting  —  A-Piers  for 
Long  Shafts — •  Erecting  an  A-Frame  Pier  —  Proportioning  Bolts  and 
Rods  —  Rolled  Thread  Lag-Screws  —  Floors  and  Flooring —  Laying  Slow- 
Burning  Flooring  —  Laying  1-  and  2-Inch  Flooring  —  Springing  2-Inch 
Planks  into  Place  —  Laying  Tongued  and  Grooved  Flooring  —  Wood 
Floors  on  Concrete  Construction  —  Hanging  Shafting  to  Concrete  Work  — 
Wall  Hangers  and  Brackets  — Methods  of  Fastening  I-Beams  — Hanging 
Shafting  to  Old  Reinforced  Concrete — Beams  and  Girders  —  A  Yoke 
Clamp  —  Erecting  Wall  Brackets  —  Drilling  Holes  in  Concrete  —  Rocking- 
Horse  Substitute  for  lack-Screw—Shaft-Supporting  Piers  —  Calculating 
the  Belt  Pull  — Working  Power  of  Belt  — Belt  Pull  on  Shaft  Supporting 
Piers —  pull  on  Working  and  on  Idle  Folds  of  a  Belt  —  Calculating 
Weight  Necessary  in  a  Pier  — Economy  of  Material  by  using  Reinforced 
Concrete  —  Calculating  Steel  Reinforcing. 


CONTENTS  3 

CHAPTER  IX. 

Roof  Timbering  and  Trusses  —  Snow  and  Wind  Loads  —  Weight  of 
Roof  Covering  — :  Roof  Trusses  —  Calculating  Strength  of  Rafters  — 
Simple  Roof  Truss  —  Weight,  Snow  and  Wind  Stresses  at  Joints  of  Truss 

—  Strains  Modified  by  Wind  Pressure  —  Stresses  Adjusted  to  Wind  Pres- 
sure —  Analyzing  the  Strains  in  a  Truss  —  The  Parallelogram  of  Forces 

—  Studying  Forces  —  Component  and  Resultant  Forces  —  Graphic  Repre- 
sentation of  Forces  —  Clockwise  and  Counter-Clockwise  —  Measuring  the 
Forces  Acting  at  a  Point  —  A   Stress  Diagram  —  Notation   for  Graphical 
Truss  Analysis  —  Constructing  a  Stress  Diagram  —  Strain  Record  —  Evo- 
lution of  the  Truss  —  Evolution  of  the  Howe  Truss  —  Evolution  of  the 
Pratt  Truss  —  Flat  Roofs  —  The  Composition  Roof  —  Laying  a  Composi- 
tion   Roof  —  Laying   Tar   and    Gravel    Roof — Tin    and   Copper    Roofs  — 
Laying   a   Tin   Roof  —  Repairing   Leaky   Tin    Roofs  —  Copper    Roofing  — 
Slate  Roofing  —  Monitors  and  Sky  Lights  —  Saw-Tooth  Lighting 

CHAPTER  X. 

Strength  of  Materials  —  Factor  of  Safety  —  Elastic  Limit  of  Soft  Steel 

—  Transverse    Strength    of    Materials  — The    Strength    of    Beams  —  The 
Moment    of    Iflertia  —  Extreme    Fiber    Stress  —  Section    Modulus  —  The 
Bending  Moment  —  Calculating  a  Beam  for  Given  Work  or  Load  —  Break- 
ing  Strength  of  Timber  —  Table  of  Moduli  of   Rupture  —  Calculating  a 
Beam — •  Crushing   Strength    and   Compression  —  Table    of  Limiting   Unit 
Stresses  — Bearing  Power  of  Bolts  and  Daps  on   Side-Wood  —  Effect  of 
Side  _  Overload    on    Bolts  —  Bearing    Plates  —  Timber-Crushing    Journal- 
Bearings  —  Bearings   which   Crush   into  the   Timber  —  Shearing   Strength 
of  Timber  —  Table  of  Shearing  Strength  of  Timber  —  Holding  Power  of 
Joint  Bolts  — Table  of  Cut  Washers  —  Resistance  to  Shearing  —  Table  of 
Cast  Washers  —  Strength  of  Ironwork  —  Table  of  Diameter,   Pitch  and 
Strength  of   Bolts  — Bolt   Failure  by   Shearing  —  Shearing   Strains   in  a 
Bolt  Head. 

CHAPTER  XL 

Laying  out  Shafting  — Horse- Power  of  Shafting  — Torsion  in  a  Shaft 

—  Twisting  Moment  of  Shafts  — Torsion  or  Stress  —  Stiffness  of  Shafts 

—  Table  of  Coefficients  of  Elasticity  —  Coefficient  of  Elasticity  for  Shear 

—  Fitting  up  a  Shaft  —  Shaft  Drawings  —  Laying  out  a  Shaft  —  Erector's 
List  of  Shafting— Fundamental   Dimensions   on   Shaft    Drawing— Shaft 
Measurements  —  Scaling   and    Measuring    Shafting — Compression    Coup- 
ling which  Holds  Fast  —  Impregnated  Stitched  Cotton  Belting  —  Defective 
Bolt  Arrangement  in  a  Compression  Coupling — Flange  or   Plate  Coup- 
ling—Improved Flange  Coupling,   The   Hendershot  —  The  Buyer's  List, 
Machinery  —  Receiving  Machinery  at  the  Mill  —  Shipping  Keys  in  Pulleys 

-Lining  Out  for  a  Shaft  —  Leveling  for  a  Shaft  —  Cutting  in  a  Pillow 
Block  — Boring  Bolt  Holes  Straight  — Bits  and  Augers. 

CHAPTER  XII. 

Putting  Pulleys  in  Place — Putting  on  a  Pulley  without  Hoisting  Tackle 
-Lining  up  Pulleys  —  Fitting  Keys  into  Pulleys  —  Double  Calipers  — 
Making  Keys  on  the  Job-- Set-Screws  — Shear  in  Set-Screws  —  Holding 
Power  of  Set-Screws  and  Keys  —  Woodruff  System  of  Keying  —  Keyways 
and  Straight  Shafting — Straightening  a  Shaft — Theory  of  Shaft  Straight- 
ening—  Setting  up  Journal  Bearing  —  Liners  for  journal  Bearings  — 
Capillary  Oiled  Bearings  —  Ring-Oiling  Bearings  —  Spring-Cover  Grease 
and  Oil-Cups  —  Oil-Cap  and  Nipple  Oilers  —  Grease-Cups  for  Journal 
Bearings  —  Ball  and  Roller-Bearings  —  Short  Life  of  Balls  in  Bearings  — 


4  CONTENTS 

Thrust  Bearings  and  Rings  —  Roller  Bearings,  Care  of  —  Pin  Bearings  — 
Six-Ball  Bearings  —  Safety  Set  Collars  —  End  Motion  to  Shaft  —  Final 
Alinment  and  Level  Test  of  Shafting  —  Double  Sighting  over  Pulleys  — 
Final  Transit  Test  of  Shafting — Rods  for  Leveling  Shafting — Plain 
Leveling  and  Alining  Rods  —  Testing  Shafts  without  the  Transit. 

CHAPTER  XIII. 

Belts  and  Belting — Belt- Width  Diagram,  A  —  Laying  out  a  Belt  Power 
Diagram  —  Pulley,  Belt  and  Horse-Power  Diagram  —  Uses  of  the  Belt 
Diagram  —  Finding  the  Length  of  Belts  —  Length-of-Belt  Chart,  Laying 
out  a  —  Length-of-Belt  Chart  —  Selecting  Belting  —  Requirements  of 
Leather  Belting — Selecting  Rubber  Belts  —  Impregnated  Stitched  Cotton 
Belt  —  Data  Required  for  Selecting  Gandy  Belts  —  Pick,  Weave,  Stretch 
and  Weight  of  Duck  — Oil  and  Paraffin  Filling  for  Gandy  Belt  —  Belt 
Fastenings  —  Lacing  Belts  —  A  Weak  Belt  Joint :  Holes  too  Large  —  A 
Good  Belt  Joint :  Holes  Correctly  Proportioned  —  Bristol  Belt  Hooks  — 
Blake's  Belt  Studs  — Jackson  Steel  Wire  Belt  Lacing— The  Creep  of  Belts 

—  Putting  Belts  on   Pulleys  —  Rope-Hitch  for  Belts. 

CHAPTER  XIV. 

Setting  up  Machines  —  Skids  and  Rollers  —  The  Wrhisky  Jack  —  Oper- 
ation of  Whisky  Jacks  —  Bali-Bearing  Screw-jack  — •  Caution  when  Jack- 
ing-Up  Machinery  —  Using  Skids  and  Rollers  —  The  "Holler  Boss"  — 
Using  Differential  Chain  Hoists  —  Caution  when  Hoisting  Machinery  — 
Wire  Cable  and  Snatch-Block  Method  of  Hoisting — Strength  of  Wire 
Cable  — Table  of  Iron  and  Steel  Wire  Cable— Wire  Cable  and  Snatch-Block 
Hoist — Strength  of  Iron-Strapped  Blocks  —  Table  of  Working  Strength 
of  Blocks  —  Placing  Machines  upon  Foundations  —  Lever  and  Cable-Hoist 
Lift  —  Fitting  a  Machine  to  its  Foundation  —  The  Plaster  Method  of 
Machine  Setting — Setting  Machines  with  Cement,  Plaster  and  Brimstone 

—  Alining    Shafting    with    a    Plumb-Bob  —  Belt    Shifters   and    Shifting  — 
Ordinary   Belt   Shifter— Rope   and   Rod   Belt    Shifters  — Distant   Control 
Belt  Shifters  —  Rope  Controlled  Belt  Shifters. 

CHAPTER  XV. 

Babbitting,  Scraping  and  Lubricating  —  Table  of  Bearing — Metal 
Alloys  —  Preparing  Bearings  for  Babbitting — Drying  Bearings  with  Gaso- 
line —  Covering  Mandrels  with  Paper  —  Peening  Soft  Linings  —  Putty  or 
Clay  Dams  —  Forming  Oil-Channels  —  Heating  Babbitt  Metal  —  Pouring 
Soft  Metal  Bearings  —  Pouring  Thin  Solid  Boxes  or  Bearings  —  Scrap- 
ing Bearings  —  Tools  for  Scraping  Bearings  —  Side  Scraper  for  Journal 
Bearings  —  End  Scraper  for  Fast  Work  —  Automatic  Lubrcation  —  Chain 
or  Ring  Lubrication  —  Circulating  Oil  System  —  Oil  Filters  and  Pumps  — 
Oils  and  Oil  Testing — Glass,  Oil  Test  —  Oil  Testing  Machine  —  Grease 
Lubrication  —  Albany  Grease  —  Lubricants  for  Different  Purposes  —  Cold 
Test  for  Oils. 

CHAPTER  XVI. 

Steam  and  Water  Pipe  Fitting  —  Laying  put  a  Steam  Line  —  Rule 
of  Thumb  Pipe  Calculations  —  Triangle  of  Pipe  Diameters  —  Off-Hand 
Method  of  Pipe  Calculation  —  Nominal  and  Actual  Diameters  of  Pipes  — 
Selection  of  Pipe  and  Fittings  —  Eastern  and  Western  Pipe  Standards  — 
Standard  Pipe  Fitting — Standard  Valves  —  Piping  for  Service  or  for 
Profit  —  Laving  out  Piping — Perspective  Pipe  Lav-Out  —  Pipe  Shown  in 
Isometric  Perspective  —  Measuring  Pip^  Lines  —  Cutting  off  Pipe  —  Use 
of  the  Hack-Saw  for  Cuttine  Pipe  —  Thr«ndinor  Pipe  —  Keep  the  Tools 
Sharp  —  Defective  Pipe  and  Fittings  —  Finding  Obscure  Leaks  in  Pipes  — 
Draining  Pipe-Systems  —  "Cutting"  of  Valves  and  Fittings  —  Pipe  Tongs 


CONTENTS  5 

and  Their  Use  —  Abuse  of  Pipe  Tools  —  Air  and  Water  Traps  —  Dead- 
Ends  and  Drips  —  The  Steam  Loop  —  Making  up  Flange  Connections  — 
Badly  Arranged  Pipe  Connections  —  Expansion  of  Steam  Pipes — Coeffi- 
cient of  Expansion  of  Iron  —  Boilers  Properly  Piped  —  Packing  and  Re- 
grinding  Valves  —  Making  up  Pipe  Joints  —  Cutting  Gaskets  and  Packing. 

CHAPTER  XVII. 

Erecting  Steam  Engines  —  Foundations  to  Absorb  Vibrations  —  Sus- 
pended Foundations  —  Always  use  a  Templet  —  Setting  Anchor  Bolts 
with  the  Transit  —  Constructing  a  Templet  —  Laying  Out  —  Setting  up  a 
Templet  —  Placing  Engines  upon  Green  Foundations  —  Foundation  Bolts 
and  Pockets  —  Who  shall  Furnish  Anchor  Bolts  —  Alining  the  Engine  — 
Personal  Examination  of  Work  during  Erection  —  Cross  for  Centering 
Head  End  of  Cylinder  —  Adjusting  the  Engine  Center  Line  —  Centering 
Line  in  Gland  —  Fastening  the  Engine  Bed  in  Position  —  Squaring  the 
Engine  Shaft  —  Checking  Alinment  of  Engine  Shaft  —  Adjusting  the 
Engine  Main  Bearing  —  Equalizing  the  Clearance  —  Putting  on  an  Engine 
Pulley  —  Tightening  Pulley  Bolts  and  Links  —  Putting  on  the  Engine 
Belt  —  Engine  Governor  Belt  —  Testing  an  Engine  Governor  Belt  —  Run- 
ning Engines  Over  or  Under  —  Water  Separator  and  Cylinder  Lubricator 

—  Exhaust  and  Drip  Pipes,  and  Heater. 

CHAPTER  XVIII. 

Steam  Boiler  Setting  —  Locating  the  Steam  Boiler  —  Excavating  for 
Boiler  Foundations  —  Starting  the  Boiler  Brickwork  —  Plan  for  Setting  a 
Horizontal  Boiler  —  Fire-Brick  Furnace  Lining  —  Side  Elevation  of  Hori- 
zontal Boiler  Setting  —  Lugs  for  Supporting  a  Steam  Boiler  —  The  Back 
Arch — Boiler  Feed  Pipe — Boiler  Blow-Off  Pipe  —  Cleaning  Door  and 
Back  Combustion  Chamber  —  Safety  Valve  and  Steam  Pipe  Connections 

—  Stop  and  Check  Valves  —  Boiler  Grates  and  Doors  —  Boiler  Stack  and 
Damper  —  Boiler  Feeding  Appliances  —  Connecting  the  Injector  and  Feed 
Pump  —  Automatic  Boiler  Feed  —  High  Duty  Boiler  Feed  Pumps  —  Steam 
Traps  —  Coal  and  Ash  Handling. 

CHAPTER  XIX. 

Some  Shop  Work  —  Making  Wooden  Rolls  —  Rig  for  Boring  Rolls  — 
Turning  Rolls  without  a  Lathe  —  Making  Long  Rolls  —  Pod-Auger  for 
Roll-Boring — Boring  Straight  Holes  —  Method  of  Straight  Hand  Boring 

—  Inserting      Roll      Gudgeons  —  Split-Ring      for      Roll-End  —  Finishing 
Wooden    Rolls  —  Lagging    Pulleys   to    Increase   their    Diameter  —  Making 
and  Laying-Out  Lag  Patterns  —  Building  a  Wood  Pulley  on  a  Flange  — 
Preparing  and  Using   Glue  —  Hot  and  Cold   Glue  —  Bits  and   Boring  — 
Bits  for  Repair  Work  —  Reaming   and   Enlarging   Holes  —  Boring   Long 
Holes  —  Boring  thru  Knots  and  Spikes  —  Small  Bits  —  Sharpening  Bits  — 
Repairing  Damaged  or  Worn  Bits  —  Expanding  a  Bit. 

CHAPTER  XX. 

Water  Wheel   Setting  —  Flume   Construction  —  Deck  Flume   Framing 

—  Turbine  Wheel  Setting  —  Gear  or  Belt  Transmission  —  Pen  Stock  and 
Draft-Tube    Wheel    Setting  — Wheel    Setting    Then    and    Now  — Water 
Wheel  Governors  —  Framing  for  Wheel  Shafts  —  Pen  Stock  Building  — 
Spill-Ways  and  Waste  Waterways  —  Canals  and  Wheel  Pits  —  Founda- 
tions in  Bog  and  Quicksand  —  Dams  and  Aprons  —  Wire-Cloth  Dam  for 
Alluvial  Streams  —  Setting  Hydraulic  Rams  —  Ratio  of  Lift  and  Fall  in 
Hydraulic    Rams  —  Efficiency   of    Hydraulic    Rams  —  Water    Supply   and 
Pumping  for  Steam  and  Fire  —  Fire  Hydrants  and  Hose  —  Locating  and 
Piping  Automatic  Sprinklers. 


MILLWRIGHTING. 


CHAPTER  I. 

THE  MILLWRIGHT  AND  WHAT  HE  Is. 

The  millwright  is  a  "man  who  builds  mills."  So  says  Webster 
in  his  dictionary.  Some  enterprising  millwrights,  particularly  as 
soon  as  they  begin  to  make  plans  for,  as  well  as  to  build  mills,  be- 
come tired  of  the  time-honored  name  of  "millwright"  and  term 
themselves  "mechanical  engineers."  Webster  also  says  that  "En- 
gineering is  the  science  and  the  art  of  utilizing  the  forces  and 
materials  of  nature."  Thus  the  millwright  has  a  perfect  right 
to  the  more  ambitious  title.  If  he  chooses  to  write  M.  E.  after 
his  name,  no  man  can  forbid;  but  to  maintain  his  title  he  must 
"deliver  the  goods"  and  prove  himself  capable  of  making  the 
very  best  possible  use  of  the  time,  material  and  conditions  which 
he  is  working  with. 

The  ancient  type  of  millwright  has  passed  away.  He  has  gone 
with  the  old-time  carpenter  and  the  obsolete  shoemaker — the 
former  with  500  pounds  of  molding  planes  and  wood-working 
tools,  the  latter  with  nothing  but  pegging  and  sewing  awls,  ham- 
mer and  knife.  It  used  to  be  said,  so  leisurely  were  the  move- 
ments of  the  typical  millwright,  as  he  pared  for  hours  and  days 
on  the  teeth  of  a  single  mortise-gear,  that  "A  drop  of  a  mill- 
wright's sweat  would  kill  a  toad/'  The  modern  millwright  is  a 
pretty  lively  proposition.  He  is  a  wide-awake  man  who  works 
with  brains  as  well  as  with  his  hands.  He  is  supposed  to  take  the 
more  or  less  perfect  plans  from  the  designing  engineer — who 
desires  to  reserve  the  title  of  C.  E.,  or  M.  E.,  entirely  for  himself, 
and  who  often  refers  to  the  millwright  as  a  "carpenter" — to  exe- 
cute these  plans,  and  in  many  instances  to  complete  the  details 
and  to  supply  most  if  not  all  the  minor  engineering,  to  finish  the 

7 


8  MILLWRIGHTING 

work  of  the  designer,  to  cover  his  mistakes  and  to  help  him  out 
generally.  Often  the  millwright  must  make  his  own  plans  if 
he  has  any.  It  is  therefore  very  hard  to  designate  just  where 
the  mechanic  becomes  the  engineer,  but  as  the  millwright  utilizes 
the  forces  and  materials  of  nature,  he  is  surely  an  engineer  and 
entitled  to  the  name  and  credit  thereof — when  he  does  the  work. 

QUALIFICATIONS  OF  A  MILLWRIGHT. 

The  millwright  must  be  a  worker.  There  is  no  room  for  drones 
in  this  branch  of  mechanical  industry.  The  millwright  must  also 
be  a  student.  He  has  much  to  learn  and  no  longer  has  to  acquire 
it  all  by  word  of  mouth,  as  was  the  case  with  old-school  mill- 
wrights. The  modern  millwright  must  have  a  pretty  good  tech- 
nical education  in  order  to  be  of  use  in  his  vocation.  He  must 
be  able  to  calculate  strains,  strength  of  materials,  and  the  result- 
ants of  forces.  As  a  draftsman  the  millwright  must  be  able  to 
make  and  read  drawings,  to  calculate  foundations,  and  to  build 
them.  He  must  also  understand  how  to  work  in  wood  and  in 
metal.  He  must  be  a  good  blacksmith,  a  first-rate  carpenter  and 
pattern  maker ;  must  know  how  to  put  a  pattern  in  the  sand  and 
the  resulting  casting  into  the  lathe. 

He  must  be  mason  enough  to  set  a  steam  boiler  in  first-class 
shape  and  steam-fitter  enough  to  pipe  the  boiler  in  the  best  pos- 
sible manner.  The  millwright  must  also  be  a  good  business  man, 
and  be  able  to  buy  machinery  and  supplies  to  advantage.  He  fre- 
quently needs  to  be  a  good  bookkeeper  and  has  lots  of  corre- 
spondence to  look  after  and  answer.  The  ability  to  handle  men 
is  another  qualification  which  must  be  possessed  by  the  mill- 
wright, who  must  also  be  able  to  set  up  and  run  all  kinds  of  steam 
machinery  and  who  also  must  understand  the  erection  of  about 
every  machine  ever  invented.  In  addition  to  this,  the  modern 
up-to-date  millwright  must  have  a  good  working  knowledge  of 
electricity,  and  be  able  to  set  up  and  operate  motors,  generators, 
transformers,  electric  lights,  bells  and  all  ordinary  electrical  con- 
traptions. 

STUDY  METHODS. 

To  be  able  to  do  all  the  things  enumerated  above,  the  mill- 
wright must  study,  and  study  hard.  He  must  take  advantage  of 


THE   MILLWRIGHT   AND   WHAT   HE   IS  9 

what  other  people  have  done  and  begin  where  they  left  off.  He 
must  read;  not  only  books,  but  technical  papers  of  all  kinds. 
Above  all,  when  the  millwright  reads  or  sees  something  which 
he  does  not  understand,  he  must  proceed  at  once  to  study  the 
matter  and  to  work  back  until  he  arrives  at  a  point  where  his 
knowledge  equals  the  demands  made  upon  it.  Then,  from  that 
point,  let  him  work  forward,  mastering  the  subject  thoroughly, 
one  step  at  a  time,  until  he  has  acquired  sufficient  knowledge  to 
understand  the  matter  in  question. 

Let  the  millwright  form  the  fine  habit  of  studying  to  the 
source,  anything  which  he  hears  or  sees  but  which  he  does  not 
understand,  and  he  will  soon  be  of  greater  value  to  his  employer, 
and  capable  of  commanding  a  greatly  increased  salary. 

STEEL  AND  TIMBER  FRAMING. 

The  framing  of  timber  is  one  of  the  millwright's  most  fre- 
quently used  accomplishments,  and  modern  practise  demands  that 
the  millwright  be  able  to  design  and  construct  concrete  piers  and 
other  structures.  Structural  steel  also  must  be  mastered  so  that 
it  can  be  handled  when  called  for.  Lots  of  machinery  nowadays 
is  set  upon  steel  instead  of  timber,  and  the  standard  connections 
used  in  steel  work  must  be  familiar  to  the  millwright  so  that 
no  time  may  be  lost  in  getting  ready  for  such  work  when  called 
upon  to  do  it. 

Steel  bridge-trees  and  harness  work  for  shafting  is  so  dif- 
ferent from  the  old-time  wood  construction,  that  considerable 
study  must  be  put  in  upon  the  strength  and  stiffness  of  steel 
shapes.  Even  in  steel,  or  in  concrete,  what  answers  for  today 
may  be  obsolete  tomorrow,  calling  for  constant  study  upon  the 
part  of  the  millwright  in  order  that  he  may  be  up  to  date  with 
the  latest  plans  that  are  put  out  by  structural  concerns.  Even 
with  the  time-honored  wood  construction  there  have  been  great 
changes  in  construction.  The  time-honored  mortise  and  tenon 
have  almost  entirely  disappeared  in  mill  work,  and  the  "box," 
"dap"  or  similar  uniting,  reinforced  with  a  bolt  or  two,  has  taken 
the  place  of  the  timber-weakening  mortise.  In  fact,  so  greatly 
has  the  method  of  framing  changed  that  the  writer  cites  the  in- 
stance of  a  large  factory  of  which  he  is  now  completing  the 
plans,  and  he  cannot  call  to  mind  a  single  mortise  and  tenon  in 
the  entire  framing. 


10  MILLWRIGHTING 

Thus  the  millwright  must  be  on  the  alert,  all  the  time,  con- 
stantly absorbing  new  things  and  advanced  practise.  He  can 
not  afford  to  ignore  what  is  going  on  around  him,  or  he  may 
fail  to  recognize  some  valuable  item  of  progress.  The  millwright 
must  be  a  hustler — first,  last,  and  all  the  time. 


CHAPTER  II. 

FACTORY  LOCATION. 

Not  the  least  of  the  millwright's  duties,  and  one  which  he 
is  frequently  called  upon  to  carry  out,  is  the  location  of  a  factory, 
buildings,  yards,  and  perhaps  railway  tracks  and  even  a  canal, 
wheel-pit  and  tail-race.  Such  work  properly  belongs  to  the  engi- 
neer who  has  to  aid  him  in  the  transit  and  level,  and  a  well 
equipped  force  of  men,  engineers  and  draftsmen,  who  are  spe- 
cialists in  that  kind  of  work.  But  this  makes  no  difference. 
Frequently  the  millwright  has  it  all  to  do,  and  the  better  he  is 
fitted  for  such  work,  the  better  will  be  the  results  he  achieves. 

For  laying  out  factories,  no  general  rules  can  be  given.  Each 
proposition  must  be  studied  in  the  light  of  its  own  surroundings, 
and  the  best  any  millwright  or  any  civil  or  mechanical  engineer 
can  do,  is  to  obtain  the  very  best  results  possible  from  the  condi- 
tions and  material  which  are  present.  No  man  can  do  more,  and 
the  result,  whether  achieved  by  an  eminent  engineer  or  by  an 
humble  millwright,  is  somewhere  between  best  or  worst,  accord- 
ing to  the  skill  with  which  the  work  is  done.  The  writer  has  seen 
factories  which  were  laid  out  by  both  kinds  of  men  noted  above. 
He  has  seen  some  millwright  results  which  put  to  shame  some 
work  put  out  by  the  engineers — and  he  has  also  seen  some  which 
told  exactly  the  opposite.  But,  good  millwright  or  good  engineer, 
the  result  is  good.  Bad  engineer  and  poor  millwright  turn  out 
bad  results,  almost  invariably. 

MOVEMENT  OF  MATERIAL  DURING  MANUFACTURE. 

One  fundamental  rule  to  be  followed  in  laying  out  any 
factory,  manufacturing  plant,  or  other  industrial  undertaking 
is  this:  In  all  plans  and  designs,  see  that  the  course  of  the 
material  under  operation  is  forward,  in  one  general  direction, 
from  the  point  where  raw  material  is  received  toward  the  shipping 
platform  where  finished  products  are  to  be  delivered,  ready  for 
shipment.  It  must  be  kept  well  in  mind  that  any  deviation  of  the 
course  of  material,  from  a  straight  line  between  these  two  points, 

11 


12  MILLWRlGHTING 

surely  results  in  increased  cost  of  construction.  It  costs  money 
to  handle  material,  even  to  convey  it  from  machine  to  machine 
in  the  factory,  to  elevate  it  from  one  floor  to  another,  and  even 
to  put  in  and  take  out  of  machines.  Therefore,  if  the  material, 
through  bad  planning,  must  be  carried  up  to  another  floor  of  the 
factory  after  having  once  been  there  in  the  regular  course  of 
progression,  then  the  efficiency  of  the  layout  is  not  as  great  as  it 
might  be,  and  the  man  who  laid  out  the  factory,  or  the  process, 
is  at  fault. 

If  material,  after  having  passed  a  given  point  in  the  factory, 
has  to  be  carried  back  again  to  some  machines  which  have 
been  passed  in  the  journey  of  progression,  then  the  factory  scheme 
js  defective.  It  may  be  very  slight,  but  it  is  capable  of  improve- 
ment, and  evidently  is  not  "the  best  possible  arrangement  of  the 
forces  and  materials  of  nature,"  hence  the  result  is  poor  engi- 
neering— or  poor  millwrighting. 

SAWMILL  ARRANGEMENT. 

If  a  sawmill  is  to  be  built,  the  millwright  will  see  to  it  that 
the  logs  come  into  the  mill  in  the  easiest  possible  manner,  and  so 
that  they  do  not  interfere  with  the  exit  of  the  finished  product. 
It  certainly  is  very  poor  judgment  to  so  arrange  a  mill  yard  that 
the  slabs  from  a  log  band-saw  interfere  with  the  hauling  of  logs 
into  the  mill.  It  is  not  at  all  desirable  to  find  a  mill  floor  so 
arranged  that  the  finished  product  from  a  flooring  machine  seri- 
ously interferes  with  the  room  necessary  for  feeding  material  to 
a  stave  saw.  Such  things  determine  the  skill  of  the  man  who 
has  been  entrusted  with  the  work,  to  do  which  acceptably  he  must 
use  brains. 

LACK  OF  WORKING  SPACE  AROUND  MACHINES. 

A  frequent  cause  of  poor  factory  arrangement  is  the  failure 
of  the  designer  to  properly  comprehend  the  amount  of  working 
space  necessary  between  and  around  the  several  machines.  Many 
factory  layouts,  which  look  splendidly  on  paper,  are  found  utterly 
worthless  when  executed,  owing  to  the  serious  lack  of  room  for 
the  handling  of  material  in  process  of  manufacture.  It  requires 
much  more  space  than  appears  necessary  at  first  sight,  and  the 
inexperienced  designer  almost  invariably  fails  to  give  working 
space  enough — he  never  was  known  to  give  too  much. 


CHAPTER  III. 

LAYING  OUT  THE  BUILDINGS. 

Much  of  this  part  of  the  work  has  already  been  decided  upon 
as  shown  in  Chapter  II,  therefore  this  chapter  will  deal  more  with 
the  actual  work  of  laying  out  the  foundations.  A  man  has  be- 
fore him  four  ways  of  doing  the  work  which  it  is  proposed  to 
name  and  describe  in  the  order  of  their  value,  the  first  method 
being  the  best  should  be  used  by  all  means,  provided  the  tools, 
instruments  and  appliances  necessary  for  the  work,  can  be 
obtained. 

METHODS  OF  LAYING  OUT  FOUNDATIONS. 

I.  By  the  use  of  the  engineer's  transit. 

II.  By  the  use  of  the  builder's  level. 

III.  By  the  use  of  the  carpenter's  level. 

IV.  By  the  use  of  the  tape  line  and  pole. 

There  are,  however,  several  things  in  common  with  all  four 
methods  which  will  be  described  in  the  first  method.  Other 
things  will  be  described  as  they  are  reached  in  the  several  methods. 
The  first  methods,  as  above,  are  by  means  of  the  engineer's 
transit  and  level,  the  latter  commonly  known  as  a  "Y"  level. 
It  is  known  by  that  name  for  the  reason  that  the  frame  supporting 
the  telescope,  somewhat  resembles  the  letter  Y.  The  first,  as 
stated,  is  the  best  and  most  costly  method  ( for  the  instrument,  the 
operation  itself  is  the  cheapest)  of  all  and  it  is  preferable  to  all 
other  ways  of  laying  out  buildings,  foundations,  or  any  other  work 
whatsoever. 

But  the  millwright  does  not  always  have  an  engineer's  transit 
in  his  tool  box.  Such-  an  instrument  costs  anywhere  from  $100 
to  $600  although  the  writer  has  upon  several  occasions  obtained 
a  good  serviceable  second-hand  transit  for  $60  and  the  purchase 
can  frequently  be  duplicated  in  the  second-hand  stores  of  large 
cities. 

13 


14  MILLWRIGHTING 

There  is,  however,  a  form  of  instrument  known  as  "Bostronr  s 
Improved  Builders'  Level,"  which  is  evidently  for  millwrights' 
use,  as  well  as  for  architectural  work,  and  which  in  addition  to 
laying  out  any  building  he  will  ever  be  called  upon  to  construct, 
may  also  be  used  for  the  aligning  of  shafting  and  other  mill- 
wrighting  work. 

THE  BUILDER'S  LEVEL. 

This  little  appliance,  which  is  used  in  the  second  method  to  be 
described,  is  made  in  Atlanta,  Ga.  It  is  given  to  the  trade  as  an 
absolutely  reliable  instrument  for  architects,  builders,  carpenters, 
stone-masons,  and,  we  may  add,  millwrights.  It  can  be  used  for 
any  kind  of  foundation  work  and  for  getting  angles.  It  is  simple 
in  its  construction,  easily  understood  and  can  be  operated  by  any- 
one who  will  be  likely  to  be  called  upon  to  lay  out  a  building. 
It  is  made  of  oxidized  brass  and  has  a  silvered  circle  of  degrees. 
It  has  an  achromatic  telescope  of  ample  power  for  such  work, 
and  the  price,  including  plumb-bob,  tripod,  graduated  measuring 
rod  and  target  is  only  $25.  While  this  is  not  a  high-grade  instru- 
ment, it  is  sufficiently  accurate  for  the  purpose,  and  any  building 
operation  can  be  carried  out  with  one  of  these  instruments  which 
is  within  the  reach  of  any  millwright,  and  should  be  a  part  of  his 
stock  of  tools. 

But  very  little  space  will  be  devoted  to  this  the  second  method 
of  laying  out  foundations,  as  the  man  who  has  purchased  one  of 
the  builder's  levels  will  soon  qualify  himself  to  use  that  instru- 
ment, which  is  used  in  much  the  same  way  as  the  engineer's 
transit;  therefore  the  directions  given  for  laying  out  lines  with 
that  instrument  apply  also  to  the  builder's  level.  Space  can  not 
be  given  here  for  teaching  the  use  of  the  transit  or  the  level,  which 
is,  however,  a  matter  easily  acquired,  and  anyone  who  is  possessed 
of  Trautwine's  Engineers'  Pocket  Book,  or  any  other  good  refer- 
ence book  for  the  civil  engineer  will  have  no  trouble  in  learning 
to  use  the  instrument  so  as  to  do  the  work  before  him.  Therefore, 
it  will  only  be  stated  here  that  there  should  be  established — for 
this  method  and  for  the  other  methods  as  well — two  base  lines 
at  right  angles  to  each  other.  These  base  lines  really  should  be 
called  "center  lines,"  and  while  they  may  not  be  the  center  of 
anything  in  particular  but  may  be  established  outside  of  the 


LAYING  OUT  THE  BUILDINGS  15 

building  if  necessary,  they  should  be  so  made  that  all  measure- 
ments and  angles  necessary  to  the  erection  of  the  building  and 
machinery  should  be  taken  from  these  two  lines  which  are  estab- 
lished at  right  angles  to  each  other. 

CENTER,  OR  BASE  LINES. 

This  once  done,  and  the  lines  squared  with  sufficient  accuracy, 
all  other  lines  and  distances  may  be  laid  off  from  one  or  the 
other  of  the  two  lines  without  any  further  measurement  of  angles 
except  for  those  which  are  other  than  90  or  180  degrees.  By 
measuring  from  both  these  lines,  the  measurement  from  each  line 
being  parallel  to  the  other  line,  it  will  be  readily  seen  that  any 
point  may  be  located  with  great  accuracy.  Two  such  lines  should 
be  established  before  anything  else  is  done  toward  laying  out  the 
building.  These  lines  should  be  marked  with  permanent  targets, 
so  arranged  that  there  will  be  no  disturbance  of  them  during  the 
entire  subsequent  building  process. 

It  pays  to  go  to  considerable  trouble  to  put  in  stones  of  suffi- 
cient weight  that  they  may  stay  in  place,  no  matter  what  opera- 
tions are  carried  on  above  or  around  them.  Such  stones  imbedded 
in  the  ground,  level  with  the  surface  thereof  and  marked  with  a 
point,  above  which  a  plumb-line  may  be  suspended,  are  all  that  is 
required  to  permanently  locate  the  two  lines  required  for  laying 
out  any  building  by  either  of  the  four  methods  described  below. 

I.    LAYING  OUT  FOUNDATIONS  WITH  THE  TRANSIT. 

Procure  two  stones,  as  described  above,  for  each  line  to  be  laid 
out  and  locate  them  far  enough  apart  to  be  out  of  the  way  of  the 
building  operations,  and  if  convenient,  the  line  between  the  two 
stones  should  pass  through  some  portion  of  the  building  where 
the  transit  sight  will  not  be  obstructed  by  walls,  posts,  machinery 
or  partitions.  If  the  line  can  be  made  to  pass  through  doors  or 
windows  so  that  sight  can  be  had  from  one  stone  to  the  other, 
then  the  ideal  conditions  are  present.  When  this  cannot  be  done, 
the  line  should  be  established  to  one  side,  far  enough  away  that 
sight  can  be  had  past  the  outside  of  the  building. 

A  good  way  to  accurately  locate  the  points  in  the  line  where 
the  stones  are  to  be  placed  is  to  put  in  the  stones  fairly  close  to 
the  line,  using  the  transit  to  bring  them  to  the  line ;  then  locate  the 


16  MILLWRIGHTING 

exact  point  on  each  stone  and  drill  a  hole  therein.  Place  a  piece 
of  iron  in  the  hole  level  with  the  top  of  the  stone ;  fill  around  with 
lead  or  cement  and  locate  the  exact  point  in  the  piece  of  iron  with 
a  center  punch.  Care  should  be  taken  to  locate  these  stones  a 
known  distance  apart  and  an  even  number  of  feet,  in  order  that 
the  line  thus  measured  may  be  taken  as  a  base  line  if  necessary 
duiing  subsequent  operations. 

SECONDARY  LINES. 

If  the  mill  is  to  be  very  extensive,  it  will  be  necessary  to  lay 
out  other  lines  from  the  two  above  described.  Sometimes  it  is 
not  necessary  to  mark  these  "secondary  lines,"  as  we  may  call 
them,  with  such  exactness  as  was  necessary  with  the  first  two  lines. 
Still,  the  time  spent  in  permanently  locating  the  centers  will  never 
be  regretted.  It  is  to  be  understood  that  all  future  measure- 
ments are  to  be  taken  from  these  centers  and  that  the  factory  is  to 
be  erected  from  them.  In  fact,  everything  pertaining  .to  measure- 
ments in  or  around  the  factory  is  to  be  measured  from  the  two 
lines  thus  located.  A  secondary  line  may  be  necessary  in  some 
factories,  and  even  a  third  or  a  fourth  line  will  be  needed  if  the 
mill  be  an  extensive  one.  But  these  are  all  laid  off  and  measured 
from  the  main  lines  already  described.  While  it  is  an  excellent 
custom  to  permanently  locate  the  lines  from  which  the  shafting  is 
to  be  erected  with  fixed  targets  for  each  main  line  of  shafting, 
still  it  is  not  absolutely  necessary.  But  with  the  targets  perma- 
nently arranged,  the  shafting  can  be  quickly  adjusted  at  any  time 
by  the  use  of  the  transit.  The  periodical  alinement  of  shafting, 
which  is  necessary  in  every  factory  from  time  to  time,  needs  only 
the  placing  of  the  transit  on  one  of  the  stone  stations,  the  picking 
up  of  the  center  mark  on  the  other  stone  by  the  cross-hairs  of  the 
instrument,  then  a  stick  held  horizontally  against  the  shaft  to  be 
alined  is  all  that  is  necessary  for  the  quick  and  perfect  placing 
or  testing  of  the  shaft. 

PERMANENT  STATIONS  OR  TARGETS. 

Fig.  1  represents  a  form  of  permanent  station  or  target  which 
can  be  used  to  advantage — just  a  word  more  in  regard  to  the  sta- 
tion or  target  business :  The  engineer  uses  the  word  "station"  or 
"bench-mark,"  while  the  millwright  is  apt  to  term  a  point  a  "tar- 


LAYING  OUT  THE  BUILDINGS 


17 


get,"  for  the  reason  that  to  mark  such  a  point,  he  is  in  the  habit 
of  nailing  a  piece  of  board  upon  a  timber  and  marking  the  line 
thereupon  as  shown  by  Fig.  2,  in  which  a  represents  the  piece 
of  board  referred  to;  b,  the  timber,  and  d,  a  line  marked  upon 
the  board.  This  line  is  usually  made  by  marking  down  beside  a 


100' 


FIG.   1.— PERMANENT    STATION    OR    TARGET. 

spirit  level  (plumb)  with  a  pencil,  or  the  line  is  located  with  a 
plumb-bob  and  afterwards  pencil-marked  upon  the  board  a. 

At  the  point  from  which  a  string  is  to  be  suspended  or  attached, 
to  lead  off  to  a  similar  target  at  the  other  end  of  the  line,  he 
makes  a  mark  that  can  be  more  easily  attached  to  than  that  of 
a  pencil.  As  soon  as  he  is  certain  or  satisfied  that  the  string  is 


18 


MILLWRIGHTING 


in  its  proper  place,  he  marks  it  by  means  of  a  saw-cut,  c,  which  is 
let  into  the  top  of  the  board  as  shown.  This  cut  is  for  convenience 
in  attaching  a  string,  which  is  simply  slipped  into  the  saw-cut 


FIG.    2.— THE  MILLWRIGHT  "TARGET." 

and  pulled  tight  against  a  loop  knot  which  should  always  be  tied 
in  the  end  of  such  a  string.  The  other  end  of  the  string  should 
be  slipped  into  a  similar  saw-cut  in  another  target  and  made 
fast  by  winding  the  string  a  couple  of  times  around  a  timber, 
or  around  a  couple  of  nails  placed  convenient  to  the  saw-cut  for 
that  purpose. 

STATION  POINTS  AND  STONES. 

The  point  in  Fig.  1  may  be  called  a  target  if  desired,  but 
more  strictly  speaking  it  is  a  station  point.  The  indentation  in 
the  iron  is  shown  by  a,  the  iron  itself  by  &,  and  the  cement  or  lead 
setting  by  c.  The  stone  is  represented  by  d,  which  usually  is  a 
portion  of  a  cobble,  split  six  or  eight  inches  square;  the  only  re- 
quirements being  that  it  is  large  enough  so  that  it  will  stay  in 
place  and  not  be  unduly  moved  by  the  work  of  teams  or  men 
around  it,  or  by  wet  weather  and  frost. 

This  stone  is  represented,  both  in  plan  and  in  elevation  or  sec- 
tion, as  set  in  the  ground  e,  which  is  tamped  closely  around  the 
stone  at  the  time  it  is  set,  which  should  be  a  considerable  time 
before  it  is  used  in  order  that  there  should  be  no  change  in  posi- 
tion of  the  stone  through  the  settling  of  the  ground.  Not  only 
should  the  soil  be  well  tamped,  but  it  is  well  to  fill  the  hole  with 
water  after  the  stone  has  been  put  in  place,  and  throw  the  dirt 


LAYING  OUT  THE  BUILDINGS 


19 


into  the  water,  "puddling"  the  dirt  into  position,  thereby  securing 
as  firm  a  setting  as  possible  for  the  station  stone.  The  drilling 
may  be  done  before  the  stone  is  set,  but  the  iron  plug  should  not 
be  put  in  position  until  afterwards,  in  order  that  there  may  be 
opportunity  to  correct  errors  of  alinement  in  setting  the  stone  by 
moving  the  iron  center  one  way  or  the  other  as  necessary. 

ARRANGEMENT  OF  STATIONS  AND  SUB-STATIONS. 

Fig.  3  illustrates  a  method  of  arranging  stations  and  sub-sta- 
tions for  the  erection  of  a  factory  of  considerable  size.  Owing  to 
the  peculiar  arrangement  of  the  building  it  was  not  possible  to 


RD7 


FIG.  3.— A  SYSTEM  OF  STATIONS. 


run  the  main  line  through  the  center  of  the  building  or  even 
through  the  buildings  at  all,  therefore  it  was -put  to  one  side  as 
shown  by  1,  2.  The  other  main  line  however,  the  one  at  right 


20  MILLWRIGHTING 

angles  to  1,  2,  could  be  put  through  the  building,  the  doors  com- 
ing in  line,  and  this  circumstance  was  taken  advantage  of  as 
shown  by  3,  4,  which  represents  the  stones  and  stations  previously 
described.  For  the  alinement  of  shafting  in  the  two  main  build- 
ings, a  short  line,  5,  6,  was  put  through,  taking  advantage  of  a 
door  between  the  two  buildings ;  and  another  short  line,  7,  8,  was 
placed  through  the  ell,  two  windows  coming  in  line  with  the 
stations  which  were  located  but  of  doors.  These  four  lines  were 
laid  .out  very  accurately  with  each  other  as  will  be  described,  so 
that  either  one  may  be  worked  from  with  the  assurance  that  the 
result  will  be  parallel,  no  matter  which  line  was  used. 

If  it  be  found  desirable,  other  lines  should  be  put  in,  for  it  is 
not  desirable  to  work  more  than  20  or  30  feet  on  either  side  of 
a  line  or  sub-line,  and  when  there  are  60  or  70  feet  between  sub- 
lines,  then  it  is  desirable  to  add  other  lines  as  circumstances  may 
demand.  The  manner  of  laying  out  stations  and  sub-stations 
is  also  shown  by  Fig.  3.  The  first  thing  is  to  determine  roughly 
the  lines  1,  2;  and  to  set  up  the  transit  on  Station  1,  which  may 
have  been  put  in  bodily,  the  iron  plug  put  in  place  and  the  center- 
punch  mark  duly  made.  The  transit  is  then  sighted  in  the  direc- 
tion the  line  is  to  run,  the  hole  dug  for  post  2,  the  stone  put  in 
place  and  the  center  of  the  drill-hole  brought  to  correspond 
with  the  cross-lines  of  the  transit. 

A  STATION-ROD. 

After  the  dirt  has  been  thoroughly  puddled  around  stone  2, 
the  iron  plug  may  be  set  in  place  and  the  center-punch  station- 
mark  permanently  made.  To  lay  out  stations  5  and  6,  an  entirely 
different  method  should  be  employed.  For  this  purpose,  the  writer 
prefers  to  proceed  as  shown  by  Fig.  4.  A  long  stick  about  three- 
quarters  or -one  inch  square  is  dressed  up  from  dry  lumber.  Pine 
(white)  is  the  best,  and  should  be  used  if  it  can  be  obtained  without 
too  much  trouble.  This  stick  is  made  exactly  square  and  parallel 
from  one  end  to  the  other  in  order  that  it  may  slide  readily  through 
the  gage-head  /,  shown  in  small  sketch  A,  Fig.  4.  A  marking 
point  g,  is  placed  in  the  gage-head  in  place  of  the  usual  scratch. 

The  gage-head  is  free  to  slide  the  entire  length  of  the  rod  and 
to  slide  easily,  but"  the  head  may  be  locked  at  any  point  by  means 
of  the  thumb-screw  shown.  The  other  end  of  the  stick,  or  rod, 


LAYING  OUT  THE  BUILDINGS 


21 


has  a  line  squared  around  it  as  shown  at  e.  Two  bits  of  wood 
are  glued  and  nailed  to  opposite  sides  of  the  rod  and  the  mark 
squared  around  them  also.  These  pieces  are  for  the  purpose  of 
"squaring"  the  rod  to  the  transit,  as  will  be  made  plain  later.  The 
line  around  the  rod  at  e  is  merely  a  knife-mark  extending  entirely 
around  the  stick.  The  mark  had  best  be  made  before  the  side 
pieces  are  added,  then  the  line  should  be  extended  across  them 
after  they  are  fastened  in  place. 

The  use  of  the  rod  may  be  best  understood  by  referring  to  the 
main  portion  of  Fig.  4,  where  the  transit  being  set  up  over  sta- 
tion 1,  at  a,  and  sighted  to  the  center-point  at  station  2,  the  rod 


FIG.  4.— LAYING  OUT   SUB-STATIONS—STATION-ROD. 

or  pole  is  placed  at  a  c,  extending  from  station  1  to  station  3. 
The  point  g  upon  the  gage-head  is  brought  to  the  center  of  the 
drill-hole  in  the  station  stone,  then  the  rod  is  carefully  lifted  and 
carried  to  the  other  end  of  the  line  where  it  is  put  in  position  as 
shown  by  bd;  the  end  b  of  the  rod  is  so  located  that  the  mark  on 
the  rod  is  "picked  up"  (sighted  into  line  with  the  transit  cross- 
hairs), then  it  is  noted  whether  the  point  at  d  comes  in  or  near 
the  drill-hole  of  station  stone  4.  If  the  point  comes  too  close  to 
one  side  of  the  drill-hole,  it  must  be  set  back  a  trifle,  and  then  the 
iron  plug  placed  in  one  side  of  the  drill-hole  at  d,  and  upon  the 
opposite  side  of  the  drill-hole  at  station  3. 

USING  THE  STATION-ROD. 

If  the  rod  is  used  in  connection  with  the  transit  when  setting 
the  station  stones,  there  will  be  no  trouble  in  this  direction,  and  the 
holes  can  be  brought  into  alinement  while  the  stones  are  being 
set.  But  great  care  must  be  taken  that  the  measuring  rod  is  at 
all  times  level  and  held  perpendicular.,  to,  or,  as  the  millwright 


22  MILLWRIGHTING 

calls  it,  "square"  with  the  transit  line.  To  make  sure  of  the  latter 
condition,  the  strips  of  wood  on  the  measuring-rod  were  placed  at 
€,  as  described.  The  manner  in  which  the  pieces  help  square  the 
rod  is  by  lengthening  the  line  which  has  been  drawn  around  the 
rod,  thus  enabling  the  transit-man  to  help  the  rodman  square  the 
rod  by  means  of  the  line  mentioned. 

If  the  rod  lies  perfectly  square  (perpendicular)  with  the  station 
line,  the  mark  on  e  will  coincide  with  the  cross-hairs  in  the  transit. 
But  if  the  rod  leads  off  at  an  angle,  no  matter  how  slight,  the 
transit-man  can  detect  it  and  direct  the  rodman  to  move  one  end 
of  the  rod  to  the  right  or  to  the  left  as  may  be  necessary  in  order 
to  make  the  entire  length  of  the  mark  e  coincide  with  the  cross- 
hairs. The  longer  the  mark  at  e  the  greater  the  accuracy  in  bring- 
ing this  line  to  bear  with  the  cross-hairs,  hence  the  lengthen- 
ing of  that  line  by  the  addition  of  the  pieces  in  question.  Be 
sure  that  the  rod  is  level  while  taking  measurements.  A  small 
level,  known  as  the  "which  way"  level,  is  screwed  to  the  rod  as 
shown  at  h.  These  levels,  as  the  name  indicates,  act  both  laterally 
and  crosswise,  hence  the  name — "which  way."  They  are  in  use 
a  great  deal  upon  photographic  cameras  and  can  be  purchased 
for  a  very  small  sum. 

LONG  AND  SHORT  STATION-RODS. 

For  some  kinds  of  work  a  long  rod  will  be  necessary,  while  in 
other  cases  a  short  rod  will  answer  as  well.  The  writer  has  used 
long  rods,  short  rods  and  sectional  rods  which  could  be  spliced 
together  to  any  desired  length,  but  he  found  it  better  to  make  at 
least  three  rods,  one  30  feet  in  length,  one  10  and  one  20  feet. 
With  these  three  rods  any  distance  up  to  30  feet  may  be  handled 
on  each  side  of  the  line,  making  60  feet  reach  in  all.  For  longer 
reaches  than  60  feet,  there  should  be,  as  stated  elsewhere,  another 
station  line  put  in,  as  30  feet  is  enough  to  measure  with  a  pole. 

LAYING  DOWN  CROSS-LINES. 

Having  put  in  stations  1  and  2,  Fig.  3,  also  stations  5  and 
6,  the  stations  7  and  8  can  be  put  in  in  the  same  manner  that 
stations  5  and  6  were  placed.  Next  comes  the  locating  of  the 
cross-station  line  3  and  4.  There  are  several  ways  of  laying  out 
this  line ;  the  way  most  in  use  is  to  set  up  the  transit  on  station  2, 


LAYING  OUT  THE  BUILDINGS  23 

pick  up  station  1  with  the  transit  cross-hairs,  turn  the  graduated 
limb  of  the  instrument  90  degrees  and  use  the  pole  and  scratch 
point  for  locating  stations  3  and  4.  Another  way  is  to  set  up 
the  instrument  on  station  3,  with  the  instrument  directly  over 
the  center-punch  mark  which  has  been  put  in  place.  Then  use 
the  rod  in  picking  up  stations  1  and  2,  reversing  the  transit  to 
do  so.  When  this  has  been  accomplished,  turn  off  90  degrees  on 
the  transit  limb  and  establish  the  marks  3  and  4  as  directed  for 
locating  other  stations  directly  in  the  transit  line.  It  sometimes 
happens  that  station  2  can  be  used  for  both  lines  1  and  2,  and 
for  3  and  4.  In  cases  of  this  kind,  it  will  only  be  necessary  to 
turn  off  90  degrees  on  the  limb  of  the  transit  and  put  in  station  4. 

ADVANTAGES  OF  THE  STATION-ROD  METHOD. 

Another  very  good  way  is  to  put  station  3  directly  in  line 
with  stations  1  and  2.  Then  lay  off  the  90  degree  line  with  a 
single  setting  of  the  transit  on  station  3.  This  is  a  handy  method 
and  should  be  used  whenever  possible.  Millwrights  and  engi- 
neers as  wet!  will  find  this  rod  method  of  laying  out  foundations 
a  very  handy  way.  It  is  fully  as  accurate  as  turning  two  corners 
with  the  transit  and  measuring  the  distances  with  the  steel  tape 
between  the  lines  of  the  stations.  It  also  has  the  advantage  that 
it  does  not  require  one-half  the  time.  The  station-rod  shown 
by  Fig.  4  is  also  excellent  for  alining  shafting.  It  may  be  used 
as  shown  with  no  change  whatever  where  the  ends  of  the  shaft 
can  be  gotten  at,  and,  with  the  addition  of  a  little  appliance  to 
be  described  later,  nothing  further  is  necessary  for  getting 
shafting  into  line  accurately  and  speedily. 


CHAPTER  IV. 

THE  BUILDER'S  LEVEL  AND  FOUNDATIONS. 

The  Builder's  Level,  as  briefly  described  elsewhere  and  as 
shown  by  the  engraving  of  the  instrument,  which  enables  the 
millwright  to  see  exactly  what  the  tool  looks  like,  is  a  small  level 
with  a  graduated  limb  attached.  This  being  the  case,  the  di- 


FIG.  5.— THE  IMPROVED  BUILDER'S  LEVEL. 

rections  given  for  laying  out  foundations  with  the  transit  will 
apply  equally  to  the  builder's  level.  But  nothing  has  been  said 
yet  about  finding  the  level  of  the  foundations.  This  part  of  the 
work  will  be  described  later,  and  it  may  be  done  either  with  the 
transit,  the  Y  level,  or  with  the  builder's  level.  It  may  be  done 
at  the  same  time  or  just  after  the  foundations  are  laid  out. 

When  working  with  the  builder's  level,  the  station  stones 
may  be  put  down  exactly  as  described  when  they  are  located 
with  the  transit.  The  iron  plugs  may  be  put  in,  the  punch-marks 
located  exactly  as  described  and  the  several  lines  may  be  picked 
up  and  located  in  precisely  the  same  manner.  In  fact,  the  en- 
tire description  of  the  method  employed  with  the  transit  may  be 
applied  directly  to  use  with  the  builder's  level. 

24 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS     25 

COST  OF  STONE  STATIONS. 

It  is  extremely  possible  that  the  cost  of  putting  in  the  stone 
stations  above  described  will  be  more  than  the  management  de- 
sires to  be  subjected  to.  This  is  extremely  likely,  and  in  eight 
cases  out  of  ten  the  millwright  must  content  himself  with  wooden 
stakes  driven  into  the  ground,  and  nothing  more  permanent  is 
usually  provided,  even  for  future  use.  This  is  surely  a  mistake, 
but  often  the  owners  cannot  be  brought  to  see  it,  neither  can  they 
be  compelled  to  put  in  the  permanent  stations  which  are  desirable 
in  more  ways  than  one. 

When  wooden  stakes  must  be  used  for  stations,  procure  them 
at  least  3  inches  in  diameter.  A  square  stake  is  best,  but  of  course 
round  stakes  can  be  used  if  necessary  and  they  may  be  cut  from 
pieces  of  cord-wood  if  nothing  better  can  be  obtained.  The  iron 
plug  and  center-punch  mark  is  dispensed  with  and  a  tack  driven 
into  the  end  of  the  stake  answers  the  purpose,  though  consider- 
ably less  accurate  than  the  plug  and  center-punch  mark.  The 
writer  brings  to  mind  one  instance  where  the  management  would 
not  stand  for  putting  in  station  stones,  but  they  were  induced  to 
put  in  concrete  blocks  wherever  it  was  desired  to  have  a  perma- 
nent station  located. 

CONCRETE  STATION  STONES. 

To  this  end,  holes  were  made  with  an  ordinary  post-digger; 
a  hole  about  8  inches  in  diameter  and  18  inches  deep  was  dug 
into  the  soil  which  was  quite  free  from  stones.  These  holes 
were  located  with  the  instrument  and  were  placed  very  accu- 
rately. Some  concrete  was  mixed  up,  being  made  of  sand  and 
gravel,  and  the  holes  filled  with  that  mixture  which  was  tamped 
into  place  as  solidly  as  possible. 

After  the  concrete  had  partially  hardened,  a  railroad  spike 
was  driven  in,  in  place  of  the  iron  center  called  for  by  the  stone- 
post  method.  In  some  instances  common  spikes  were  used,  and 
in  a  few  cases  bits  of  round  iron  were  cut  off  a  %-inch  rod  and 
driven  into  the  concrete  for  the  center-plugs.  After  the  cement 
had  set  for  three  days,  the  spikes  were  marked  with  a  center- 
punch  in  the  manner  described  for  method  I.  This  concrete 
method  of  making  station  stones  is  a  very  desirable  one  and  does 
not  cost  as  much  as  to  split  out  ordinary  stones,  dig  holes,  put 


26  MILLWRIGHTING 

the  stones  in  place  and  puddle  them  fast  in  the  ground.  Gravel 
concrete  is  plenty  good  enough  for  stations  of  this  kind  and  they 
are  very  cheap,  the  only  expenditure  being  for  the  cement  which 
should  be  mixed  with  the  sand  in  the  proportion  of  about  one  to 
four. 

THE  DETERMINATION  OF  FOUNDATION  LEVELS. 

Having  found  the  points  upon  the  stations  corresponding  to 
the  several  lines  necessary  for  the  work,  some  attention  may  be 
given  to  the  leveling  before  going  further  with  the  foundation 
work  itself.  Where  the  characteristics  of  the  ground  will  per- 
mit, the  entire  factory  arrangement  should  be  placed  upon  the 
same  level,  but  where  the  ground  is  uneven,  it  may  be  found 
necessary  to  lay  out  a  portion  of  the  factory  on  a  higher  or  a 
lower  level  than  the  rest  of  the  building.  This  matter  will,  of 
course,  be  governed  by  the  plans.  It  is  the  millwright's  business 
to  find  the  hights  or  grades  given  by  the  drawings  and  to  repro- 
duce them  at  the  building  site  by  means  of  stakes,  targets,  or 
other  marks  to  which  the  workmen  can  bring  the  several  grades 
proposed  or  required  in  the  building  operations. 

The  entire  operation  of  leveling  by  means  of  a  transit  or  by 
the  Y  level  or  the  builder's  level  can  be  brought  down  to  a  very 
simple  matter.  First,  the  instrument  itself  is  brought  to  an 
accurately  level  position  by  means  of  the  screws  or  other  means 
provided  for  that  purpose.  Then  the  cross-hairs  in  the  tele- 
scope are  brought  to  bear  upon  a  mark  on  a  stick  or  a  target 
which  in  turn  has  been  placed  vertically  upon  one  of  the  sta- 
tion marks.  The  stick  or  rod  is  then  carried  to  another  station 
and  the  telescope  of  the  leveling-instrument  is  revolved,  without 
permitting  it  to  depart  from  its  level  position,  until  it  bears  fair 
upon  the  rod  in  its  new  location.  A  second  sight  is  then  taken 
at  the  rod  upon  the  second  station,  and  the  point  where  the  cross- 
hairs cut  the  rod  is  noted.  The  difference  between  the  two 
points  on  the  stick  or  station-rod  represents  the  difference  of 
level  between  the  two  stations.  The  marks  made  with  the 
instrument  sighted  at  stations  1  and  2  will  represent  the  hight  of 
the  cross-hairs  of  the  instrument  above  the  stations  mentioned. 
It  is  not  necessary  that  the  hight  of  the  instrument  be  any  par- 
ticular figure.  In  fact,  it  may  not  even  be  known,  and  no  atten- 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS    27 


tion  may  be  paid  to  that  matter  as  all  the  calculations  and  meas- 
urements can  be  made  without  this  distance  being  taken  into 
account. 

Almost  any  stick  may  be  used  for  a  station-rod  or  leveling- 
rod,  but  good  tools  always  pay,  and  if  the  millwright  does  not 
feel  inclined  to  purchase  a  leveling-rod  with  his  instrument — a 
small  one  is  included  in  the  cost  of  the  builder's  level,  while  an 
elaborate  affair  is  usually  supplied  extra  with  the  transit  or 
with  the  Y  level — then  he  may  easily  construct  a  serviceable  rod 
for  himself. 

HOME-MADE  LEVELING-ROD  OR  STAFF. 

Fig.  6  will  give  an  idea  of  how  to  make  up  this  instrument. 
The  square  rod  a  is  about  %  or  1  inch  on  a  side,  while  for 
heavier  work  it  would  be  well  to  have  a  larger  rod,  say 
V/2  inches  square.  Another  ordinary 
gage-head  is  used,  and  in  the  engraving 
the  same  head  is  used  wriich  was  shown 
in  Fig.  4,  the  scratch  point  b  having 
been  removed  by  unscrewing  it,  the 
hole  remaining  visible  at  c,  as  noted. 

An  oval  with  rather  extended  width, 
is  cut  out  of  pine  lumber,  say  1% 
inches  thick,  and  a  square  groove  is 
cut  through  its  center  to  receive  rod 
a,  as  shown  in  Fig.  6,  in  which  e  d 
represents  the  pine  oval  in  question, 
with  the  rod  a  sliding  through  it  flush 
with  the  face  of  the  disk  or  oval.  Com- 
mencing at  the  lower  end,  the  rod  is 
graduated  into  feet  and  tenths  of  a  foot, 
although  architects  sometimes  use  rods 
graduated  into  feet  and  inches,  but  the 
decimal  form  of  notation  will  be  used 
in  the  following  paragraphs.  The 

rod  divided  in  feet  and  tenths  is  known  as  the  ''engineer's  rod," 
while  the  feet  and  inch  division  belongs  to  the  architect's  rod. 
The  same  rod  can  be  graduated  upon  two  sides  and  both  forms  of 
graduation  used  as  either  is  desired. 


FIG.    6.— LEVELING-ROD. 


28  MILLWRIGHTING 

THE  VERNIER  SCALE-MAKING  AND  READING. 

On  the  front  side  of  the  rod,  the  heavy  shaded  figure  shows 
one  of  the  foot  marks,  the  lighter  figures  and  graduation  denote 
inches  or  tenths  of  a  foot,  according  to  the  graduation  used,  the 
reading  upon  the  rod  as  shown  by  Fig.  6  being  upon  the  decimally 
divided  graduation,  and  denotes  4.09  feet.  At  g  is  shown  a  short 
scale,  known  as  the  vernier  scale;  this  is  easily  read  off  by  the 
millwright.  It  is  contained  upon  a  purchased  rod,  but  may  be 
easily  constructed  if  necessary.  To  lay  out  a  vernier,  simply  lay 
down  eleven  of  the  ten  parts  into  which  a  unit  is  divided,  then 
divide  the  space  thus  laid  out  into  ten  portions,  the  same  as  the 
inch  or  other  unit  is  divided.  In  this  case,  one-tenth  of  a  foot  and 
one  one-hundredth  of  a  foot  (or  one  inch  and  one-tenth  of  an 
inch)  is  laid  off  on  the  little  scale  g,  and  then  spaced  and  divided 
into  ten  equal  portions  as  shown  in  the  engraving. 

Each  space  upon  the  vernier  scale  g  now  represents  11/10 
one-hundredths  of  a  foot  (or  tenths  of  an  inch).  To  read  the 
vernier,  by  means  of  which  the  millwright  is  enabled  to  read  the 
rod  down  into  thousandths  of  a  foot,  it  is  only  necessary  to  take 
the  reading  on  rod  a,  to  the  line  /,  which  is  the  mark  which  is 
the  closest  to  a  line;  that  is,  read  to  the  line  on  a,  which  is  first 
below  /.  This  gives  feet,  tenths  and  hundredths  of  a  foot — or 
tenths  of  an  inch.  To  get  thousanths  of  a  foot  or  hundredths 
of  an  inch,  start  from  the  bottom  of  the  scale  g  and  count  up  to 
that  one  of  the  lines  in  the  vernier  scale  g  which  coincides  with 
one  of  the  lines  on  a.  The  third  line  upon  g  coincides  with  a  line 
on  a,  thus  three  one-thousandths  of  a  foot  is  to  be  annexed  to  the 
direct  reading  taken  from  the  rod  a,  and  the  line  /,  on  the  disk, 
making  the  complete  rod  reading  4.093  feet.  Thus,  in  taking 
any  reading,  the  rod  reading  is  taken  first,  then  the  vernier  read- 
ing is  added  or  annexed  to  the  rod  reading. 

USE  OF  THE  LEVELING-ROD. 

Fig.  7  wilt  give  a  slight  idea  of  the  manner  in  which  the  level- 
ing-rod  is  used  in  laying  out  foundations.  This  engraving  repre- 
sents a  portion  of  a  foundation  in  plan,  also  in  elevation,  the  lat- 
ter showing  a  portion  of  wall  100  feet  above  datum  line  and 
another  portion  of  the  same  wall,  101  feet,  5  inches  above  datum 
line.  By  datum  line  it  is  understood  that  an  imaginary  line  is 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS     29 

taken  far  enough  below  the  foundations  that  nothing  about  the 
building  will  ever  be  placed  lower  than  the  line  in  question. 
This  line  may  be  assumed  at  any  level  below  the  foundation,  and 


100' 


101'  5" 


PJaa 


FIG.    7.— LEVELING    FOUNDATIONS    WITH    A    CROSS-HAIR 
INSTRUMENT. 

in  this  case  it  has  been  assumed  that  the  datum  line  is  100  feet 
below  the  foundation,  or  that  portion  of  the  foundation  which  is 
marked  with  that  figure. 


30  MILLWRIGHTING 

A  leveling-rod  is  shown  at  a  on  the  100-foot  level  and  also 
at  b  on  the  101-foot,  5-inch  level.  At  g  is  one  of  the  station 
stones  previously  described,  and  its  level  is  98  feet,  6  inches  as 
marked.  It  will  be  noted  that  the  bottoms  of  the  foundations 
are  respectively  96  feet,  and  97  feet,  5  inches,  thereby  giving  the 
same  hight  of  foundation  both  at  the  100-foot  level  and  at  the 
101-foot,  5-inch  level.  Referring  to  the  plan  view  in  Fig.  7,  an 
instrument  is  shown  upon  its  tripod  at  g,  and  directed  at  the 
leveling-rod  d  upon  the  100-foot  level.  First,  however,  the  tran- 
sit or  level  should  be  directed  to  station  /,  and  a  reading  taken 
upon  the  rod,  the  instrument  being  leveled  at  g,  and  there  may 
be  indicated  upon  the  rod,  4  feet  2  inches,  or,  if  an  engineer's 
rod  be  used,  4.166  feet,  this  measurement  being  recorded  in  the 
book  and  the  rod  moved  to  a,  and  another  reading  taken  to  test 
the  wall  at  that  point. 

As  the  level  required  at  d  is  exactly  100  feet,  it  is  evident 
that  the  wall  at  that  point  should  be  18  inches  higher  at  the 
point  than  at  station  f,  and  that  the  reading  on  the  rod  at  a  (or 
d)  of  5  feet  8  inches,  may  be  shortened  18  inches,  becoming  4 
feet  2  inches,  and  this  distance  may  be  read  off  upon  the  rod  and 
the  sliding  head  adjusted  to  that  length  of  rod.  Then  placing 
the  rod  at  b,  plan  view,  and  pointing  the  instrument  toward  it, 
the  cross-hairs  of  the  instrument  should  cut  the  line  across  the 
disk  of  the  rod  if  the  level  or  hight  of  the  wall  is  as  required.  If 
the  wall  is  higher  or  lower,  the  sliding  head  of  the  rod  must 
be  moved  up  or  down  to  make  the  cross-hairs  of  the  instrument 
intersect  the  center  line  of  the  disk,  and  the  error  in  the  hight 
of  the  wall  is  the  difference  in  reading  of  the  rod,  from  the  4  feet 
2  inches  mentioned  above. 

In  a  similar  manner,  the  instrument  may  be  swung  around 
and  pointed  toward  e  (in  the  plan)  which  corresponds  with  b 
in  the  elevation,  and  a  similar  reading  taken.  In  this  manner, 
required  tests  are  made  of  the  hights  of  the  walls  in  question. 
It  will  be  noted,  by  referring  to  the  elevation  in  Fig.  7,  that  the 
disks  on  all  three  rods  shown  in  their  different  positions  are 
at  exactly  the  same  level.  This  is  the  principle  of  leveling  with 
a  cross-hair  instrument.  The  disks  are  at  all  times,  by  means  of 
the  instrument,  brought  to  the  same  level,  no  matter  where  they 
are  placed;  therefore  the  hights  of  the  several  walls  or  stations 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS     31 

can  be  read  directly  from  the  rod,  and  by  subtracting  one  from 
the  other  the  difference  in  elevation  between  any  two  of  the 
points  or  levels  is  readily  ascertained. 

Perhaps  the  above  statement  should  be  qualified  a  little,  for 
instead  of  reading  directly  upon  the  rod  the  hight  of  any  station 
or  wall,  there  is  read  the  hight  of  the  instrument  above  that  wall 
or  station,  and  by  adding  this  reading  to  the  hight  above  datum 
line  of  any  known  wall  or  station,  a  working  distance  is  obtained 
from  which  the  readings  obtained  from  the  different  levelings 
will  give  directly  the  hights  of  the  points  or  walls  from  which 
such  readings  were  taken.  It  therefore  becomes  apparent  that 
every  time  the  instrument  is  set  up  it  may  be  at  a  different  hight, 
and  a  new  reading  must  be  taken  from  some  point  of  known 
hight  before  the  level  of  any  wall  can  be  compared  to  the 
required  level. 

PLUMBING  THE  LEVEL-ROD. 

Referring  again  to  Fig.  6,  the  leveling-rod  and  its  horizontal 
line,  it  will  be  noted  that  this  line  is  placed  across  both  sides  of 
the  disk,  and  that  the  disk  is  extended  considerably  on  each  side 
of  the  rod.  This  is  for  the  purpose  of  enabling  the  transit-  or 
level-man  to  note  whether  or  not  the  rod  is  placed  in  a  perpen- 
dicular position,  and  the  transit-man  will  instruct  the  rod-man 
to  move  the  rod  in  such  a  manner  that  the  horizontal  line  will  be 
brought  to  coincide  with  the  horizontal  cross-hair  of  the  instru- 
ment, much  in  the  same  manner  the  vertical  cross-hair  was 
brought  into  use  when  the  measuring-rod  was  squared  up  as 
already  described. 

BATTER  BOARDS. 

In  order  to  properly  lay  out  the  foundations  for  a  building 
after  the  station  stones  have  been  put  in  place,  it  is  necessary  that 
some  means  be  devised  for  fastening  lines  which  must  be  stretched 
tightly  in  the  direction  in  which  the  masonry  is  to  be  built.  For 
this  purpose  a  couple  of  boards  and  some  stakes  are  erected, 
usually  as  shown  by  Fig.  7,  which  represents  the  average  method 
of  doing  a  job  of  this  kind.  The  boards  as  erected  are  shown  at 
a  and  b,  and  are  known  as  "batter  boards."  It  will  be  noticed 
that  the  stakes  have  been  driven  in  any  old  manner  and  that  the 


32  MILLWRIGHTING 

boards  were  nailed  on  haphazard  without  regard  to  level  or  dis- 
tance from  the  lines.     Batter  boards  thus  erected  are  always  a 


FIG.    8.— THE    USUAL    APPEARANCE    OF   BATTER    BOARDS. 

nuisance.  First,  they  are  sure  to  come  in  the  way  of  the  dirt 
heap ;  next,  the  boards  being  placed  too  low,  the  masonry  runs 
up  above  them  and  they  are  useless  in  that  direction. 

LOCATING  AND  ERECTING  BATTER  BOARDS. 

But  to  proceed  with  these  batter  boards :  From  the  station 
stones,  lines  are  run  parallel  to  a  and  b,  which  in  Fig.  7  repre- 
sents one  of  the  chalk  lines  (or  other  lines)  in  position  for  the 
face  of  the  wall,  stretched  tightly  from  batter  board  a  to  another 
batter  board  at  the  opposite  end  of  the  wall.  A  similar  line  is 
stretched  from  board  c  to  another  board  placed  beyond  d,  which 
is  not  shown  in  the  engraving.  Chalk  lines  a  b  and  c  d  are  then 
squared  up  with  the  transit  in  the  same  manner  as  that  described 
for  locating  station  lines  and  stones.  Line  a  b  represents  the 
location  of  the  face  of  one  of  the  foundation  walls,  while  line  c  d 
represents  the  face  of  the  cross  wall — the  same  wall,  in  fact, 
which  is  shown  by  Fig.  7.  But  the  batter  boards  as  arranged  in 
Fig.  8  are  an  unmitigated  nuisance  and  should  not  be  tolerated. 

The  proper  method  of  arranging  batter  boards  is  shown  some- 
what in  detail  by  Fig.  9,  and  an  entirely  different  arrangement  is 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS    33 

shown  by  this  engraving.  The  batter  boards  are  set  nearly  square 
and  the  ends  are  brought  to  a  level.  They  are  also  set  back  out 
of  the  way  of  the  earth  which  has  been  thrown  out  and  the 
boards  are  also  out  of  the  way  of  material  which  must  be  placed 
near  the  excavation. 


FIG.  9.— BATTER  BOARDS  ERECTED  TO  GRADE. 

It  will  be  noted  that  the  top  of  one  of  the  boards  is  marked  "100 
feet."  This  part  of  board  a  is  level  with  the  top  of  the  wall  when 
it  is  completed.  Instead  of  two  boards  and  four  posts,  both 
boards  are  nailed  to  a  common  post  /,  thereby  forming  a  braced 
corner  which  is  very  stable.  Posts  i  and  k  are  set  back  out  of  the 
way  of  the  lines.  In  the  preceding  engraving  the  chalk  lines  are 
shown  wound  around  the  batter  boards  and  attached  to  nails 
driven  into  the  boards  for  that  purpose. 


34  MILLWRIGHTING 

LOCATING  AND  FASTENING  CHALK  LINES. 

Nails  may  be  used  in  the  arrangement  shown  by  Fig.  9,  but 
after  the  lines  have  been  located,  we  will  take  the  line  a,  for 
example,  which  corresponds  to  a  similar  line  in  Fig.  8.  This  line, 
after  it  has  been  located  on  batter  board  a,  also  upon  the  distant 
batter  boards,  is  marked  with  a  pencil  in  the  precise  location  it 
is  to  occupy.  After  the  line  b  has  been  located  in  a  similar  man- 
ner, and  after  the  lines  have  been  marked  on  the  other  batter 
boards  in  a  similar  manner,  a  saw-cut  is  run  in  a  small  fraction 
of  an  inch  as  shown  at  e,  a,  c,  g  and  at  /,  b,  d,  h. 

SAW-CUTS  IN  BATTER  BOARDS. 

The  cuts  a  and  c  are  the  outside  and  inside  faces  of  the  wall. 
The  cuts  e  and  g  are  the  outside  and  inside  faces  of  the  footing 
of  the  wall,  so  that  in  starting  the  brickwork  the  mason  only  has 
to  stretch  the  line  at  c  and  g,  then  after  the  footing  has  been  com- 
pleted, he  moves  the  lines  to  cuts  a  and  c  and  goes  ahead  with 
the  body  wall.  He  proceeds  in  a  similar  manner  with  lines  at 
/  and  h,  and  b  and  d.  This  throws  all  the  work  of  the  location 
and  level  of  the  wall  upon  the  engineer  or  millwright,  also  the 
responsibility  therefor. 

Once  the  batter  boards  are  accurately  located,  there  is  nothing 
more  to  do  except  to  construct  the  wall.  To  erect  batter  boards 
in  this  manner,  the  post  j  is  first  located  and  driven  and  the  posts 
i  and  k  are  afterwards  located  and  driven  solidly  into  the  ground. 
It  is  not  necessary  to  square  these  posts  by  means  of  the  instru- 
ment. Any  angle  85  to  95  degrees  will  answer  and  the  posts 
can  be  placed  accurately  enough  by  the  eye,  the  only  requirement 
being  that  they  are  set  back  out  of  the  way  of  workmen  and 
material. 

Boards  12  to  16  feet  long  should  be  used  and  placed  as  far 
back  as  possible  and  still  have  room  for  the  lines  upon  them. 
The  posts  having  been  located,  take  a  reading  on  /  with  the  level- 
ing-rod,  the  instrument  being  set  up  to  read  from  one  of  the  sta- 
tions. Mark  the  grade  100  feet  on  one  of  the  posts,  transfer  the 
reading  to  each  of  the  other  posts  and  they  are  ready  for  the 
boards  to  be  nailed  on. 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS    35 

PUTTING  UP  BATTER  BOARDS. 

It  is  best  for  three  men  to  do  the  work  of  putting  up  battef 
boards — one  man,  a  carpenter,  with  boards,  hammer,  saw  and 
nails ;  the  transit-  or  level-man,  and  the  rod-man.  The  reading 
having  been  made  and  marked  at  /,  put  one  nail  in  board  a,  fasten 
the  board  to  post  /,  exactly  upon  the  mark  100  feet,  then  the 
rod-man  will  place  his  rod  upon  the  free  end  of  the  board  at  k, 
keeping  the  same  reading  on  the  rod  which  was  marked  upon  /. 
He  will  move  the  rod  and  the  board  bodily  up  and  down  until 
the  transit-man  signals  that  the  mark  on  the  rod  cuts  the  cross- 
hairs of  the  instrument.  Then  the  carpenter  will  nail  the  board 
to  both  stakes,  testing  at  /  after  the  boards  have  been  nailed  to 
see  that  the  level  has  not  been  changed  during  the  nailing  opera- 
tion. Test  in  like  manner,  after  nailing,  board  b,  after  it  has 
been  nailed  to  board  i  in  the  manner  described. 

Referring  again  to  Fig.  7,  it  will  be  noted  that  there  is  a  jog 
in  the  surface  of  the  wall,  shown  by  Fig.  9.  It  is  also  shown 
by  Fig.  7  that  the  wall  is  to  be  4  feet  high,  the  top  being  marked 
100  feet,  the  bottom  96  feet,  and  the  jog  being  laid  down  as  97 
feet  5  inches  and  101  feet  5  inches  respectively.  As  shown  by 
Fig.  9,  the  pit  must  be  dug  to  the  depths  noted  above,  thus  making 
17  inches  difference  in  the  levels  of  the  two  portions  of  the  wall. 

READING  THE  LEVELING-ROD. 

It  should  be  thoroughly  understood  by  the  millwright  that  the 
reading  on  the  leveling-rod  which  gives  100  feet  on  top  of  the 
batter  board,  when  the  transit  is  set  in  a  certain  position,  may 
not  give  that  level  when  the  transit  is  placed  in  another  position. 
The  reading  on  the  rod  will  vary,  to  give  100  feet,  according  to 
the  level  at  which  the  transit  happens  to  be  set  up.  The  reading 
on  the  leveling-rod,  to  give  100  feet  on  the  batter  board,  may 
be  3  feet  6  inches,  or  3  feet  8  inches,  or  it  may  be  some  other 
reading  according  to  the  hight  at  which  the  instrument  happens 
to  be  leveled  up.  Therefore,  bear  well  in  mind  that  the  rod  read- 
ing changes  every  time  the  instrument  is  set  in  a  different  place, 
and  that  it  is  by  no  means  necessary  to  always  place  the  transit 
or  level  in  the  same  spot  when  "throwing  lines  or  levels." 

But  having  found  the  distance  on  the  rod  which  will  give  a 
grade  of  100  feet  elevation,  it  is  only  necessary  to  add  2  feet  6 


36  M1LLWRIGHTING 

inches  more  to  the  reading  in  order  to  give  the  97  feet  6  inches 
reading  on  the  rod,  which  will  locate  the  97-foot  6-inch  level 
required.  A  very  little  practise  in  this  direction  will  enable  the 
millwright  to  use  the  leveling-rod  with  equal  facility  which  he 
shows  in  using  the  measuring-rod,  as  described  in  a  previous  chap- 
ter. Machinery  foundations  may  be  located  in  the  same  manner 
described  for  foundations.  The  excavation  can  be  made  and 
tested  with  the  leveling-rod  in  the  same  way. 

It  is  well  to  set  each  step  of  the  foundation  work  with  the  level 
or  transit,  and  the  top  of  each  footing  may,  when  finished,  be 
checked  by  figuring  out  the  proper  reading,  taking  that  reading 
on  the  rod  placed  upon  the  finished  footing,  and  noting  whether 
the  cross-hair  cuts  the  center  of  the  target  with  the  rod  in  place 
upon  the  finished  work. 

RUNNING  LONG  LEVELS. 

A  word  of  caution  is  necessary  in  running  long  level-lines 
with  the  cross-hair  instruments  or,  in  fact,  with  any  other  instru- 
ments. When  a  line  of  more  than  100  feet  in  length  must  be 
accurately  leveled,  allowance  must  be  made  for  the  curvature  of 
the  earth  which  is  taken  as  8  inches  to  the  mile  but  is  somewhat 
modified  by  refraction,  and  it  is  well  to  allow  6.875  inches  in 
practise  to  make  up  for  the  curving  effect  produced  by  refrac- 
tion. When  running  levels  for  flowage  of  lands  by  streams  or 
ponds,  it  will  be  found  that  the  allowance  to  be  made  as  above, 
for  temperature,  as  well  as  refraction,  is  about  .002  feet  for  100 
yards,  .004  for  150  yards  and  .007  for  200  yards.  The  above 
dimensions  are  fractions  of  a  foot,  not  feet  and  inches. 

CURVATURE  OF  THE  EARTH. 

A  convenient  table  which  gives  the  allowances  to  be  added  for 
curvature  and  temperature  combined  will  be  found  on  page  163 
of  "Trautwine."  One  very  sure  method  of  running  lines  with- 
out the  necessity  of  making  curvature  corrections  is  to  place  the 
leveling  instrument  exactly  in  the  center  between  two  stations 
and  take  readings  both  ways.  This  is  the  safest  up  to  300  feet. 
Put  the  instrument  in  the  center  150  feet  from  each  station,  sight 
in  one  direction,  then  in  the  opposite  one,  and  the  result  will  be, 
provided  the  instrument  is  exactly  level,  that  the  two  points  are 


THE  BUILDER'S  LEVEL  AND  FOUNDATIONS     37 

both  of  the  same  level  by  the  instrument — that  is,  to  the  same 
curved  line  a  certain  distance  higher  than  the  instrument — but 
the  two  points  will  both  be  the  same  distance  from  the  center  of 
the  earth,  therefore  the  two  points  will  be  what  we  call  "level" 
with  each  other. 

CAUSES  OF  ERROR  IN  LEVELING. 

The  two  sources  of  error  in  determining  levels  by  means  of 
the  transit  or  the  Y  level,  or  the  builder's  level,  are  as  follows : 
First,  from  a  wrong  setting  of  the  instrument,  its  not  being 
exactly  level,  and  secondly,  by  an  incorrect  setting  or  reading 
of  the  leveling-rod.  Guard  against  these  two  possible  errors 
and  use  the  instrument  intelligently  and  there  will  be  no  trouble 
in  obtaining  accurate  levels  upon  any  job  which  the  millwright 
or  the  engineer  is  likely  to  undertake. 

Instructions  for  running  levels  with  the  Y  level  or  the  builder's 
level  cannot  be  given  in  full  here,  on  account  of  the  limited  space 
allowable  for  other  than  millwrighting  itself,  but  the  engineer 
or  the  millwright  will  have  no  trouble  in  proceeding  with  any 
work  which  may  come  to  him  provided  he  follows  the  above 
directions  in  a  thinking  manner.  "I  didn't  think"  is  the  excuse 
of  the  boy  of  today,  as  well  as  of  the  incompetent  mechanic.  A 
few  brains  are  a  good  deal  better  than  the  best,  instruments  ever 
turned  out  by  the  manufacturers.  Put  a  few  into  the  work  and 
you  will  have  little  trouble  with  almost  anything  which  you  may 
wish  to  do. 


CHAPTER  V. 

FOUNDATIONS  AND  THE  CARPENTER'S  LEVEL. 

The  next  method  of  laying  out  foundations  is  the  third — by 
the  use  of  the  carpenter's  level. 

This  way  is  usually  employed  in  connection  with  the  "tape 
line  and  pole"  method  described  in  a  following  chapter.  The 
writer  is  forced  to  acknowledge  that  this  method  of  laying  down 
elevations  for  both  building  and  machine  foundations  is  usually 
followed,  and  the  fact  is  to  be  lamented,  for  great  accuracy  is 
impossible  in  this  way,  though  with  great  care  and  much  time 
fair  results  may  be  secured. 


FIG.   10.— RUNNING  LEVELS  WITH  THE  STRAIGHT-EDGE  AND 
CARPENTER'S   LEVEL. 

The  most  common  method  of  obtaining  a  level  between  two 
points,  is  to  span  the  two  with  a  straight-edge,  place  the  level  on 
top,  as  shown  by  Fig.  10,  and  block  up  under  one  end  of  the 
straight-edge  until  the  level  bubble  comes  to  rest  in  the  center 
of  its  glass.  In  this  fairly  accurate  but  rather  slow  method,  levels 
may  be  run  from  point  to  point  as  required  by  the  work  to  be 
done,  and  whenever  the  line  approaches  within  reaching  distance 
of  a  corner  of  the  proposed  foundation,  the  straight-edge  may  be 
extended  to  that  corner  and  a  mark  made  upon  a  stake.  This 
operation  has  to  be  repeated  until  stakes  at  all  the  corners  have 
been  marked. 

In  running  levels  in  this  manner,  the  level  a  should  be  adjusted 
to  be  fairly  accurate,  though  there  is  a  method,  which  will  be 
described  later,  of  working  very  accurately  with  a  level  which 
is  pretty  badly  out  of  adjustment.  But  with  a  good  level  a,  the 

38 


FOUNDATIONS  AND  CARPENTER'S  LEVEL      39 

straight-edge  b  is  placed  upon  point  c,  which  has  been  established 
at  the  level  which  is  desired  for  the  completed  foundation.  Then 
the  outer  end  of  the  straight-edge  is  raised  to  approximate  a 
level  position,  and  an  estimate  is  made  of  the  amount  of  blocking 
required  at  d  to  reach  the  desired  level.  Then  the  straight-edge 
is  shifted  along,  the  end  c  is  turned  ahead  and  the  operation 
repeated  until  the  desired  length  of  line  has  been  leveled.  A 
straight-edge  should  not  be  used  with  the  same  end  ahead  all 
the  time  for  the  reason  that  should  one  end  be  narrower  or 
wider  than  the  other  end,  the  result  would  be  a  grade  instead  of 
a  level.  The  best  way,  under  all  circumstances,  is  to  reverse  the 
straight-edge  at  each  step  and  thus  counteract  any  error  which 
may  be  due  to  the  cause  mentioned. 

LEVELING  A  LINE  OF  STAKES. 

A  method  of  leveling  a  stake  line  is  shown  by  Fig.  11,  the  first 
stake  a,  being  used  as  a  starting  point,  and  either  cut  off  to  the 
required  level,  or  a  mark  is  made  on  the  side  to  which  the  straight- 
edge is  brought  when  starting  as  shown  at  a.  Three  men  should 


FIG.  11.— LEVELING  A  STAKE  LINE. 


attend  to  this  operation,  though  two  men  can  do  it,  but  much 
more  slowly.  With  a  man  at  each  end  of  the  straight-edge  g, 
and  another  man  in  charge  of  the  level  hf  the  work  can  be  pushed 
ahead  pretty  fast  with  a  considerable  degree  of  accuracy.  The 
supreme  test  is  to  level  entirely  around  a  foundation  and  come 
back  to  the  starting  point  without  coming  out  either  too  high  or 
too  low.  It  is  the  custom  of  the  writer  to  continually  check 
operations  each  time  the  straight-edge  is  advanced  a  length.  For 
this  purpose,  the  strip  of  board  i  is  fastened  slightly  to  post  a 
by  means  of  a  couple  of  nails :  By  sighting  back  to  the  strip  *, 
which  is  exactly  as  high  as  the  combined  width  of  level  and 


40  MILLWRIGHTING 

straight-edge,  it  is  easy  to  note  whether  the  line  is  running  level 
all  right,  or  whether  it  is  running  up  hill  or  down. 

At  post  b,  Fig.  11,  the  straight-edge  after  being  leveled,  is  held 
tightly  against  the  wood  until  it  can  be  marked  in  some  manner 
which  permits  of  no  error  in  the  level.  A  very  common  way  is 
to  put  in  a  nail  as  shown  at  b,  also  at  d  and  e.  The  straight-edge 
is  to  bear  upon  the  nail  when  the  straight-edge  is  carried  forward 
for  another  length  of  leveling.  This  is  one  of  the  most  common 
causes  of  error.  As  shown  by  sketch  A,  the  nail  should  be  put 
in  perfectly  square  with  the  post  as  at  /,  but  this  is  not  always  the 
case.  The  common  tendency  of  a  man  driving  a  nail  is  to  incline 
the  point  downward  a  little,  as  at  k,  in  which  case,  though  the 
straight-edge  /  may  have  its  night  correctly  indicated  as  it  lies 
on  the  nail  k,  there  is  a  great  chance  for  error  when  the  straight- 
edge is  passed  ahead,  for,  should  the  stakes  not  lie  quite  in  a, 
straight  line — and  they  seldom  do — the  straight-edge  will,  if  the 
stake  line  swings  to  the  left  a  little,  be  twisted  away  from  the 
stake  a  little,  and  in  order  to  take  that  position,  it  must  climb  out 
along  the  nail  a  little,  and  consequently  it  must  move  upward, 
to  the  despair  of  the  level,  as  shown  at  m,  where  the  straight- 
edge is  shown  in  its  new  and  raised  position,  throwing  the  line 
in  error  the  distance"  between  /  and  m. 

MARKING  POSTS. 

At  the  corner  post,  d,  there  is  also  great  trouble  in  placing 
the  nails  exactly  level  with  each  other  in  order  that  the  straight- 
edge may  lead  off  at  right  angles  to  its  former  course.  Some- 
times a  single  nail  is  placed  in  the  corner  of  the  post  and  both 
straigfht-edere  leads  use  that  angle  nail  in  common.  But  this 

o  o  o 

method  is  open  to  error  also,  particularly  should  the  nail  acci- 
dentally get  hit  by  something  and  assume  the  position  shown  at 
n,  sketch  A. 

It  is  much  better  to  discard  the  nail  method  and  use  pieces 
of  board  at  each  post,  as  shown  by  sketch  B.  By  this  method, 
a  bit  of  board  from  12  to  24  inches  long  is  brought  up  under- 
neath the  straight-edge  and  a  nail  previously  started  in  the  board 
is  driven  into  the  post.  Another  nail,  driven  down  to  within 
14  inch  of  its  head,  holds  the  bit  of  board  securely  and  permits 
of  no  opportunity  for  error.  The  board  is  brought  under  the 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       41 

straight-edge  in  such  a  manner  that  the  top  edge  of  the  board 
lies  level.  Fitting  the  board  against  the  under  side  of  the 
straight-edge  forces  the  former  to  assume  a  level  position,  and 
in  this  position  it  is  fastened  securely.  By  properly  locating  the 
piece  of  board  /  on  the  corner  post  d,  the  straight-edge  may  be 
placed  at  will  either  ranging  in  the  direction  it  has  been  travel- 
ing, or  the  straight-edge  may  be  turned  at  right  angles  to  the  old 
line,  in  which  case  the  straight-edge  would  rest  edgewise  upon 
the  ledger  board,  as  it  may  be  called. 

THE  RUDIMENTARY  PLANE-TABLE. 

Another  method  of  leveling  with  the  carpenter's  level,  which 
has  been  quite  extensively  employed  by  the  writer  (only  in  the 
lack  of  better  instruments)  for  laying  out  foundation  and  exca- 
vation levels :  A  level  platform  is  made  up,  say  upon  the  san4 


FIG.    12.— SIGHTING    OVER    THE    CARPENTER'S    LEVEL. 

heap  a,  and  if  possible  a  bit  of  plank  is  placed  on  the  sand  as  at  b. 
The  board  is  accurately  leveled  by  adjusting  the  sand  or  loam 
under  its  edges;  then  the  level  is  pointed  toward  a  post,  say  as 
at  d,  and  a  sight  is  carefully  taken  over  the  top  of  the  level  toward 
the  post.  An  assistant  places  his  rule  crosswise  on  that  post  and 
raises  or  lowers  the  rule  upon  signal  from  the  operator  at  the 
level.  When  the  rule  has  finally  been  brought  to  coincide  with 
the  line  of  sight  over  the  top  of  the  level,  a  mark  is  made  on 
the  post  as  at  d,  where  the  line  of  sight  cuts  the  post. 

Post  e  is  then  treated  in  like  manner,  and  all  other  points 
which  are  to  be  brought  to  the  same  level.  Points  above  or 
below  the  level  of  the  instrument  may  be  determined  by  means 
of  the  leveling-rod  already  described,  which  is  shown  at  g,  the 
lower  end  of  the  rod  being  placed  upon  the  grade  f,  the  hight  of 


42 


MILLWRIGHTING 


which  it  is  required  to  obtain.  The  reading  of  the  rod  will  give 
directly  the  difference  in  hight  between  the  grade  /  and  the 
foundation  line  d,  c,  etc. 

OPERATING  A  PLANE-TABLE. 

A  carpenter's  level  used  as  indicated  by  Fig.  12  forms  a  crude 
and  very  rudimentary  plane-table,  an  instrument  which,  when 
roughly  made  on  the  job,  is  capable  of  doing  a  lot  of  fairly 
accurate  work.  A  plane-table  set  up  ready  for  operation  is  shown 
by  Fig.  13.  This  is  a  very  crude  instrument,  but  the  amount  of 
fairly  accurate  work  which  can  be  done  with  it  can  not  be  com- 


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FIG.    13.— USING  THE   PLANE-TABLE   AND   A   CARPENTER'S 
SPIRIT  LEVEL, 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       43 

prehended  until  one  has  tried  it  for  himself.  The  table  a  is 
merely  a  well  cleated  board — a  drafting  board  answers  very  well 
— set  up  out  of  the  wind  in  a  level  position.  As  shown,  the  board 
is  supported  on  four  posts  driven  into  the  ground  and  sawed 
off  level  at  the  required  hight  of  the  foundation.  When  that 
level  is  not  convenient,  the  plane-table  may  be  set  up  at  any  con- 
venient hight  and  the  distance  to  the  foundation  line  handled  by 
the  leveling-rod. 

On  the  job  shown  by  Fig.  13,  the  plane-table  posts  c  were 
set  into  the  ground  nearly  three  feet  to  make  sure  that  they  did 
not  move  during  subsequent  operations  which  were  to  be  some- 
what complicated  and  tedious.  Ample  bracing,  which  is  not 
shown  in  the  drawing,  was  placed  on  the  posts  c,  and  four  cleats 
were  fastened  to  the  top  of  the  posts,  after  which  the  cleats  were 
dressed  off  level  to  receive  the  plane-table  board  which  was 
exposed  to  the  weather  as  little  as  possible,  being  taken  in  immedi- 
ately after  any  use  was  made  of  it. 

SETTING  BATTER  BOARDS  AND  STAKES. 

The  level  used  was  fitted  with  a  sighting  attachment,  the 
construction  of  which  will  be  described  later.  It  will  be  noted 
in  Fig.  13  that  similar  figures  refer  to  the  same  points  in  both 
plan  and  elevation,  and  that  the  later  view  shows  the  posts  in 
the  foreground  but  not  those  in  the  distance.  After  the  plane- 
table  had  been  erected  and  thoroughly  tested,  the  batter  stakes 
d,  d,  d,  etc.,  were  set  and  batter  boards  e,  e,  e  nailed  on  level  with 
the  top  of  the  carpenter's  level  b,  which  was  sighted  to  first  one 
stake  then  another,  until  all  the  batter  boards  had  been  set. 

It  will  be  noted  that  the  depth  of  excavation  and  the  top  of 
the  footings,  together  with  the  hight  of  the  finished  foundation, 
are  all  directly  controlled  by  the  leveling-rod  f,  in  the  manner 
described  in  a  preceding  paragraph.  A  single  setting  of  the  plane- 
table  support  serves  to  control  matters  until  the  foundation  is 
completed  or  the  plane-table  is  covered  up  by  the  construction 
work.  Then,  if  needed,  the  table  may  be  set  up  again  upon  some 
of  the  completed  work  and  the  operations  completed  from  the  new 
location.  It  is  best  to  so  set  up  the  plane-table  that,  if  possible,  all 
the  foundation  and  machinery  work  can  be  done  from  that 
setting  without  having  to  move  out  of  the  way  of  material  or 
construction,  but  in  many  instances  this  is  not  possible.  •* 


44  MILLWRIGHTING 

ACCURATE  SIGHTING  OVER  A  LEVEL. 

For  the  proper  sighting  of  levels,  greater  accuracy  can  be 
obtained  by  rigging  more  or  less  elaborate  attachments  to  the 
level.  It  is  quite  a  skilful  bit  of  work  to  sight  over  the  top  of  a 
level  at  a  rod  20  to  100  feet  distant  and  determine  within  1/32  of 
an  inch  where  the  mark  should  be  made.  Under  some  conditions, 
there  is  a  refraction  along  the  surface  of  the  level  which  makes 
sighting  very  hard.  A  couple  of  strips  of  equal  thickness  fas- 
tened across  the  ends  of  the  level,  as  shown  by  Fig.  14,  serve  to 
increase  considerably  the  accuracy  of  the  sighting  operation,  and 


FIG.   14.— SIGHTING   STRIPS   ARRANGED    ON    LEVEL. 

a  pair  of  rifle  sights  rigged  on  the  level,  according  to  Fig.  15, 
enable  the  millwright  to  work  with  still  greater  accuracy. 

The  strips  a  and  b  may  be  plain  pieces  of  wood,  nailed,  screwed 
or  glued  to  the  level,  or  they  may  be  metal  clips,  as  shown  by  the 
engraving.  These  clips  may  be  made  quite  strong  and  allowed 
to  remain  permanently  on  the  level  and  adjusted  to  be  true  with 
the  bottom  of  the  level.  Very  few  levels  are  found  to  be  exactly 
true  on  top,  and  the  clips  allow  adjustments  to  be  made  as 
necessary. 

"GUN-COMPASS"  LEVEL  SIGHTS. 

The  level  shown  by  Fig.  15  has  been  fitted  with  a  couple  of 
sights  somewhat  similar  to  those  used  on  a  rifle,  or  the  sights  are 
a  cross  between  those  of  a  rifle  and  of  an  old-fashioned  compass 
used  by  the  surveyors  of  90  years  ago.  The  writer  has  made 
several  sets  of  level  sights  and  usually  makes  them  from  a  couple 
of  screws  and  a  copper  cartridge  %  to  %  inch  in  diameter.  The 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       45 

arrangement  is  about  as  shown  by  Fig.  15,  the  head  of  the  cart- 
ridge being  cut  off  and  soldered  to  a  machine-screw,  which  in 
turn  fe  fitted  with  a  jamb  nut  for  holding  the  sight  in  position  after 
it  once  is  adjusted. 

A  rim  fire  cartridge  is  well  fitted  for  making  these  sights, 
about  %  or  y2  inch  of  the  closed  end  being  mounted  as  shown, 
and  a  very  small  hole  punched  or  drilled  through  the  center  of 
the  head.  This  hole  should  be  less  than  1/32  inch  in  diameter 
and  countersunk  so  as  to  leave  only  a  very  thin  edge  of  metal 
to  prevent  reflections  of  light  from  the  edge  of  the  hole. 

A  piece  of  the  body  of  the  cartridge  shell  should  be  cut  about 


FIG.    15.— LEVEL  ARRANGED  WITH   "GUN-COMPASS"   SIGHTS. 

the  same  length  as  piece  r,  and  mounted  in  a  similar  manner  as 
shown  at  d.  A  couple  of  very  small  holes  should  be  drilled 
through  the  sides  of  the  shell,  and  a  bit  of  very  fine  wire  from  the 
G  string  of  a  violin  should  be  stretched  tight  through  the  hole 
and  soldered  on  the  outside  as  shown.  These  sights  being  screwed 
into  the  brass  work  of  the  level,  they  are  ready  for  adjustment; 
should  there  be  no  brasswork,  fit  the  sights  to  wood  screws  and 
tap  them  directly  into  the  wood.  It  is,  however,  better  to  use 
either  a  brass  mounted  wooden  level,  or,  better  yet,  use  a  cast- 
iron  level  and  tap  the  sight  screws  directly  into  the  iron. 

ADJUSTING  SIGHTS  ON  A  CARPENTER'S  LEVEL. 

To  adjust  the  sights,  first  screw  them  into  place  and  arrange 

the  hole  and  the  wire  at  the  same  distance  from  the  bottom  of 

the  level  as  possible.     Place  the  level  on  a  straight-edge  and  set 

block  c  close  in  front  and  adjust  the  bolt  d  so  that  its  top  is 


46  MILLWRIGHTING 

exactly  in  line  with  the  peep  hole  and  the  wire.  Then  arrange 
two  stations  from  50  to  100  feet  apart  if  convenient;  less  will 
do,  but  the  farther  apart  the  stations  (within  seeing  limits)  the 
closer  will  be  the  adjustment  of  the  sights.  The  stations  should 
be  level  boards  or  blocks,  flat  and  out  of  wind.  Level  station  a, 
sight  the  level  to  b,  after  bringing  the  bubble  of  the  level  at  a  to 
the  center  of  the  vial;  then  adjust  the  hight  of  station  b  until 
bolt-head  d  comes  just  in  line  with  the  sights.  Next,  set  the 


FIG.  16.— ADJUSTING  SIGHTS  ON  A  LEVEL. 


block  c  on  station  a  with  the  level  adjusted  at  b,  and  see  if  the 
sights  come  in  line  with  the  top  of  bolt-head  d.  If  they  are  in 
line,  the  adjustment  is  correct.  If  the  bolt  head  appears  too 
high  or  too  low,  the  sights — one  of  them — must  be  screwed  in  or 
out  a  bit  and  the  testing  repeated  until  the  level  will  reverse 
stations  and  cut  the  top  of  bolt-head  d  every  time.  Test  the 
adjustment  of  the  level  vial  by  reversing  or  changing  the  level 
end-for-end  while  carefully  placed  on  two  level  spots.  If  the 
instrument  reverses  and  shows  the  bubble  in  the  same  place,  it 
may  be  called  accurate.  If  it  does  not  fill  the  requirement,  the 
vial  should  be  so  adjusted  that  the  level  will  reverse  as  above 
noted. 

A  HOME-MADE  LEVELING  TELESCOPE. 

The  millwright  who  desires  something  better  than  the  "gun- 
compass"  sights  illustrated  by  Fig.  15  may  make  a  telescope 
which  will  do  duty  on  the  level  when  required  and  on  a  rifle  at 
other  times.  The  principle  of  the  telescope  is  shown  by  Fig.  17, 
in  which  the  level  is  fitted  with  a  couple  of  lenses  and  a  bit  of 
shell  carrying  cross-hairs  as  shown  at  d,  Fig.  15.  In  fact,  the 
same  shell  and  hair  may  be  used,  with  the  addition  of  a  vertical 
hair,  which  would  be  an  improvement  to  d,  Fig.  15  and  which 
can  be  added  to  that  sight  permanently. 

In  selecting  the  lenses,  one  should  be  of  quite  short  focus, 
say  three  or  four  inches,  while  the  other  should  be  from  18  to 
24  inches,  accordingly  as  it  is  desired  that  the  level  be  long  or 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       47 

short.  The  length  of  the  telescope  will  be  a  little  more  than  the 
sum  of  the  focal  distances  of  the  two  lenses.  The  focus  of  a  lens 
may  be  roughly  ascertained  by  holding  it  in  front  of  a  window, 
but  preferably  as  far  back  from  the  window  as  possible,  and  then 
holding  a  piece  of  white  paper  behind  the  lens,  which  is  to  be 
moved  back  and  forth  to  and  from  the  lens  until  the  image  of 
the  window  appears  inverted  on  the  paper  as  sharp  or  plain  as  it 


FIG.    17.— CARPENTER'S   LEVEL   ARRANGED   WITH    TELESCOPIC 
SIGHTS   AND   CROSS-HAIRS. 

can  be  made  by  moving  the  paper  as  described.  The  distance 
between  paper  and  lens  will  be  the  focal  distance  of  the  latter 
and  is  conveniently  measured  by  holding  the  paper  against  the 
wall  with  one  end  of  a  rule  or  yard-stick,  while  the  lens  is  slid 
along  the  measure  until  the  image  is  as  sharp  as  it  can  be  made. 
Then  read  on  the  rule  the  distance  from  wall  to  ilens  which  is  the 
focal  distance  of  the  lens  for  objects  at  the  distance  of  the 
window. 

FOCAL  DISTANCE  OF  LENSES. 

The  less  the  distance  from  lens  to  object,  the  greater  will 
be  the  distance  from  wall  to  lens  up  to  a  certain  limit.  Beyond 
a  certain  distance,  which  may  be  termed  the  universal  focus  of  a 
lens,  there  is  little  change  in  the  distance  of  the  image  to  focus 
it  for  any  greater  distance  of  the  object.  For  the  telescope  here 
described,  borrow  the  object-glass  (the  large  one)  from  a  small 
opera-glass,  and  for  the  other  lens  take  an  ordinary  spectacle 
lens.  This  is  not  a  scientific  combination,  with  the  plain  object- 
glass  and  the  compound  eye-piece,  but  it  answers  the  purpose. 

Fit  the  opera-glass  lens  to  a  screw  stud  and  fasten  it  to  one 


48  MILLWRIGHTING 

end  of  the  level,  as  shown  at  a,  Fig.  17.  The  focal  length  of  this 
lens  having  been  measured  as  described,  lay  off  that  distance  from 
a  to  b,  and  there  locate  the  cross-hair  shell  b.  It  is  well  to  verify 
the  focal  measurement  of  lens  a  by  sliding  b  along  the  level  until 
the  cross-hairs  appear  as  sharp  and  as  clear  as  possible,  when 
looking  at  them  through  lens  a,  in  fact,  until  the  cross-hairs  are 
in  focus  with  lens  a.  Locate  the  cross-hair  shell  b  permanently 
at  that  point  and  make  sure  that  it  stands  square  with  the  lenses 
and  that  the  latter — both  of  them — when  fixed  in  place,  are  square 
with  a  line  drawn  through  the  center  of  each  lens  and  the  cross- 
hairs. Upon  the  accuracy  of  the  lenses  and  cross-hairs  in  this 
particular  depends  the  value  of  the  telescope  for  leveling  pur- 
poses. The  opticians  call  the  line  shown  by  Fig.  17,  along  which 
the  eye  is  shown  to  be  looking,  the  "line  of  collimation,"  and 
unless  both  lenses,  the  cross-hairs  and  the  eye  are  all  accurately 
located  upon  this  line,  the  instrument  will  not  work  accurately 
enough  for  leveling  purposes. 

Next,  mount  the  spectacle  lens  c  upon  a  sliding  base  and 
place  it  in  position  as  shown.  This  lens  does  the  focusing  act, 
and  it  must  be  moved  toward  the  cross-hairs  when  looking  at  a 
distance  and  away  from  the  cross-hairs  when  the  object  looked  at 
is  close  at  hand.  With  the  level  thus  arranged,  no  other  cross- 
hairs are  necessary,  but  it  is  better  to  place  a  bit  of  paper  or  thin 
metal  pierced  with  a  very  small  hole  over  the  front  side  of  lens 
a,  in  order  that  the  eye  may  more  quickly  locate  the  center  of 
the  lens  when  taking  a  sight.  Cross-hairs  are  not  required  at 
c — all  that  is  necessary  is  to  bring  the  cross-hairs  at  b  fairly  upon 
the  object,  and  then  rest  assured  that  the  telescope  and  the  level 
to  which  it  is  attached  is  pointed  squarely  toward  that  object, 
provided  that  the  three  elements  a,  b,  and  c  are  all  set  upon  the 
line  of  collimation,  as  described  in  a  preceding  paragraph. 

MOUNTING  LENSES  IN  A  TUBE. 

To  put  the  telescope  in  a  more  convenient  form,  procure  two 
pieces  of  pipe,  brass  is  preferable,  though  well  painted  iron  pipe 
may  be  used,  and  fit  one  end  of  each  pipe  with  a  screw-cap,  as 
shown  at  c  and  k,  Fig.  18.  The  pieces  of  pipe,  a  and  b,  should 
be  fitted  to  slide  snugly  inside  of  one  another.  They  should  slide 
easily  enough  to  be  readily  moved  when  focusing,  yet  they  should 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       49 

be  snug  enough  to  stay  in  place  when  moved  around  and  they 
should  not  slip  when  suspended  by  one  end.    The  cap  /  is  cut  away 


FIG.  18.— A  "SPECTACLE-PIPE"  TELESCOPE. 

as  shown,  the  full  size  of  the  inside  of  the  pipe  it  is  screwed  upon. 
Cap  c  has  only  a  small  hole  drilled  as  shown,  and  countersunk 
inside,  as  shown  at  d. 

A  "SPECTACLE-PIPE"  TELESCOPE. 

The  opera-glass  lens  is  removed  from  its  setting  and  placed 
inside  the  cap,  as  shown  at  /.  If  the  lens  is  too  large,  grind  it  to 
size  on  a  common  grindstone,  using  plenty  of  water  on  the  stone 
and  taking  care  not  to  scratch  the  face  of  the  lens.  Grind  the 
spectacle  lens  in  a  similar  manner  to  fit  in  cap  /,  as  shown  at  i. 
Place  a  bit  of  rubber  (an  elastic  band  will  do)  between  the 
lens  and  the  screw-cap  as  shown  at  e.  This  is  to  prevent  the 
cracking  of  the  lens  when  the  cap  is  screwed  up  tight  enough  to 
hold  the  lens  fast.  Another  bit  of  rubber  should  be  placed  in  a 
similar  manner  in  cap  /,  as  shown  at  k. 

MOUNTING  AND  ADJUSTING  CROSS-HAIRS — FOCUSING. 

The  cross-hair  tube  g  is  supported  by  four  machine  screws  h, 
each  tapped  into  the  tube  g  and  passing  through  holes  in  tube  a 
which  are  larger  than  the  screws,  thus  allowing  some  adjust- 
ment of  g  in  various  directions  so  as  to  bring  that  tube  to  coin- 
cide with  the  line  of  collimation.  Focusing  is  affected  by  moving 
tube  in  or  out,  and  the  tube  a  is  to  be  attached  to  the  level  and 
adjusted  from  two  stations,  as'  described  for  the  "gun-compass" 
sights.  This  telescope  will  enable  a  man  to  readily  discover  a 
nail-head  at  a  distance  of  300  to  400  feet.  It  gives  an  inverted 
image,  but  many  high-grade  transits  do  that,  and  it  is  no  objec- 
tion after  one  gets  used  to  it.  A  telescope  of  this  kind  is  known 
as  a  "night  glass,"  and  it  gives  a  better  image  in  the  dark  or 
semi-darkness  because  there  are  a  less  number  of  lenses  than 
when  an  image  right  side  up  is  given.  A  set  of  lenses  for  invert- 


50  MILLWRIGHTING 

ing  the  image  again  are  required  for  making  the  instrument  show 
things  right  side  up.  This  set  is  placed  between  /  and  i  and  merely 
inverts  the  image  again  and  incidentally  absorbs  some  of  the 
light,  hence  the  plainer  the  image  as  the  number  of  lenses  are 
decreased. 

As  A  RIFLE  TELESCOPE. 

The  telescope  as  shown  by  Fig.  18  is  an  excellent  rifle  tele- 
scope and  needs  nothing  save  being  fastened  to  the  gun  in  the 
ordinary  manner,  and,  perhaps,  the  placing  of  /  and  g  in  the 
inner  tube  so  that  the  focusing  may  be  done  from  the  front  end 
instead  of  from  the  object  end  as  now  is  the  case. 

BY  THE  USE  OF  TAPE  LINE  AND  POLE. 

The  method  of  laying  out  building  foundations  without  any 
other  instrument  than  a  chalk  line  and  a  ten-foot  pole,  applies, 
more  properly  speaking,  to  the  fixing  of  the  several  lines  and 
distances  required  for  the  location  of  foundations,  piers  and 
machines.  Really,  the  leveling  and  the  laying  out  of  wall  lines, 
etc.,  are  two  separate  and  distinct  operations,  the  lines  and  meas- 
urements require  to  be  done  before  the  levels  can  be  determined. 

But  the  problem  is,  how  to  lay  off  right  angles  and  mark 
them  without  the  use  of  the  transit,  the  builder's  level,  or  even 
the  telescope  on  the  carpenter's  level.  And  by  the  way,  the  tele- 
scope described  and  attached  to  that  instrument  will  enable  the 
millwright  to  work  with  the  station-rod  nearly  as  well  as  he 
can  with  the  transit,  the  only  difference  being  that  with  the 
transit  the  rod  could  be  observed  and  worked  at  any  hight,  while 
with  the  telescope  on  the  level  the  station-rod  must  be  brought 
into  the  line  of  sight  or  collimation,  as  the  telescope  cannot  be 
inclined  up  or  down  to  pick  up  a  sight  on  the  station-rod. 

"SQUARING"  A  LINE. 

The  time-honored  method  of  "squaring"  a  line  is  by  the  "6,  8 
and  10"  method,  as  shown  by  Fig.  19,  where  it  is  desired  to 
"square"  a  line  from  point  a  on  the  line  a  b.  The  first  step  is 
to  place  a  pin  through  the  line  at  c,  measure  off  6  feet  to  d,  and 
insert  another  pin.  Then  stretch  the  new  line  as  nearly  at  right 
angles  as  can  be  determined  by  the  eye,  measure  off  8  feet,  f,  c, 


FOUNDATIONS  AND  CARPENTER'S  LEVEL      51 

and  insert  another  pin.  Then  set  up  the  batter  boards  h,  h, 
or  place  a  couple  of  trestles  in  position  to  receive  the  pole  g  e, 
which  must  lie  just  under  the  lines,  as  close  as  possible  without 
touching  them.  Next,  adjust  line  e  f,  keeping  it  on  the  pin  at  /, 
and  moving  e  until  there  is  just  10  feet  between  e  and  g.  This 


-. -II 


FIG.    19.— THE  "6,   8  AND   10"  METHOD   OF  "SQUARING  A  LINE." 

completes  the  triangle  6,  8  and  10,  which,  according  to  geometry, 
will  require  a  right  angle  at  /,  thereby  "squaring"  line  e  /.  It  is 
necessary  that  a  good  deal  of  care  be  taken  to  keep  the  lines 
exactly  fair  with  the  pins  and  the  marks  on  the  pole.  This  at- 
tended to,  the  squaring  will  be  fairly  accurate. 

NEW  METHOD  OF  "SQUARING  A  LINE" — THE  RADIUS  BOARD. 

Another  method,  which  to  the  writer  is  entirely  new  and 
has  never  been  used  by  any  other  person,  is  as  follows :  Prepare 
a  "radius  board,"  as  shown  by  Fig.  20,  almost  any  piece  of  board 
answering  the  purpose.  The  board  can  be  made  of  any  length, 


52 


MILLWRIGHTING 


and  the  writer  usually  takes  a  12  foot  board,  %  inch  thick  by 
10  inches  wide,  and  has  a  line  drawn  from  b  to  c,  through  the 
center  of  the  board.  Next,  a  strip  of  wood  e,  a  few  inches  wide, 
has  two  nails  driven  through  it,  as  shown  at  /  and  g,  taking  pains 


FIG.  20.— RADIUS  BOARD  FOR  LAYING  OFF  A  RIGHT  ANGLE. 

to  keep  the  nails  as  square  with  the  wood  as  possible.  A  hole 
is  next  made  in  the  center  of  radius  board  a,  as  shown  at  df  and 
with  one  of  the  nails  in  the  hole  (which  may  be  made  by  driv- 
ing in  that  nail)  the  marks  b  and  c  are  made,  using  strip  e  as 
a  tram.  The  board  is  now  ready  for  business. 


FIG.   21.— "SQUARING  A  LINE"  WITH  THE  RADIUS  BOARD. 

Place  the  radius  board  on  the  ground,  as  shown  by  Fig.  21, 
with  the  strip  e  in  position  with  one  nail  in  the  center  of  board 
c,  the  other  nail  at  the  point  the  new  line  is  to  start  from.  The 
above  disposition  of  the  board  is  merely  to  locate  the  trestles  or 
batters  /  /,  which,  once  in  position,  the  board  a  is  placed  upon 


FOUNDATIONS  AND  CARPENTER'S  LEVEL       53 

them  as  shown  and  the  nails  in  e  adjusted  as  shown,  one  in  the 
hole  in  the  middle  of  the  radius  board,  the  other  nail  at  point  a, 
where  the  new  line  is  to  start.  Keep  nail  a  in  position,  and  move 
one  end  of  the  board  until  the  mark  h  lies  fair  under  the  line  b  h. 
It  makes  no  difference  whereabouts  in  line  b  point  h  is  lo- 
cated, but  the  writer  tries  to  keep  points  g  and  h  about  the  same 
distance  from  point  a,  in  order  that  the  measurements  may  be 
more  nearly  equal  as  will  be  described  in  the  next  paragraph. 
Once  get  point  h  fairly  on  line  b,  with  nail  just  at  point  a,  there 
remains  nothing  more  to  do  except  to  draw  the  new  line  from  a 
through  point  g,  and  the  lines  a  b  and  a  g  are  at  right  angles  to 
each  other,  or  "square"  as  the  old  millwrights  call  it. 

PRINCIPLE  OF  THE  RADIUS  BOARD. 

The  principle  involved  in  this  manner  of  erecting  a  perpen- 
dicular is  based  upon  that  proposition  in  geometry  which  demon- 
strates that,  "An  angle  in  a  semi-circle  is  always  a  right  angle." 


FIG.   22.— PRINCIPLE   OF  THE   RADIUS  BOARD. 

This  is  shown  by  Fig.  22,  in  which  a  b  c  form  a  semi-circle, 
and  the  lines  a  d  and  b  d  form  a  square  corner  at  d;  and  lines 
a  c  and  b  c  likewise  form  another  square  corner  at  c.  This  is 
true  of  any  and  all  lines  that  can  be  drawn  to  any  point  in  the 
circumference,  from  the  points  a  and  b. 

LEVELING  A  LINE. 

In  some  parts  of  the  country,  masons  have  a  method  of  level- 
ing quite  closely  to  a  line  stretched  between  two  points.  For 
short  spans,  as  shown  by  Fig.  23,  the  work  may  be  made  fairly 
accurate,  but  it  is  more  work  than  the  results  are  worth,  for 
they  are  always  open  to  criticism.  If  a  man  is  bound  to  attempt 
this  kind  of  leveling,  let  him  bear  in  mind  that  to  obtain  results 


54 


MILLWRIGHTING 


even  half-way  accurate,  the  level  must  be  placed  in  the  middle 
of  the  line,  equi-distant  from  its  points  of  suspension.  This  is 
plainly  shown  at  a  b  and  c,  where  the  line  a  b  is  tightly  stretched 
between  its  supporting  nails  and  the  level  c  is  set  up  exactly 
half  way  between  the  line  supporting  posts.  Should  the  level 
have  been  placed  at  e,  it  will  be  noted  that  the  line,  level  at  the 
instrument,  would  have  to  hang  from  d  instead  of  a  in  order  to 
be  found  level  at  e. 

On  longer  lines,  the  matter  is  still  more  forcibly  apparent. 
Let  Fig.  24  represent  lines  stretched  100  feet  or  more  between 
the  shed  and  the  telegraph  pole.  The  dotted  line  /  g  is  straight 
and  level.  Should  it  be  desirable  to  level  this  line  for  the  purpose 


FIG. 


-LEVELING   SHORT  LINES.       FIG.    24.— LEVELING   LONG   LINES. 


of  ascertaining  the  vertical  hight  of  points  /  and  g,  it  will  be 
noted  that  the  line,  even  when  very  tightly  stretched,  will  hang 
at  k,  where  the  level  is  in  evidence. 

But  should  the  line  have  been  stretched  between  /  and  h,  it 
stands  to  reason  that  the  line  cannot  be  level — at  least  the  points 
of  support  cannot  be  level — even  though  the  level  at  j  is  parallel 
with  the  line,  which  for  exactness  in  this  instance  is  placed  be- 
side the  line  so  that  the  two  upper  corners  of  the  level  come  fair 
with  the  line  at  either  end  of  the  level.  Although  the  points  / 
and  h  are  by  no  means  found  to  be  level,  it  is  demonstrated  that 
the  points  /  and  m  are  in  the  same  level  line,  also  that  the  points 
/  and  n  are  also  level  when  the  level  is  placed  at  /,  and  that  the 
distance  /  /  is  equal  to  /  n,  and  that  distance  /  /  is  also  equal  to 


FOUNDATIONS  AND  CARPENTER'S  LEVEL      55 

distance  /  m.  That  points  j  and  n  came  vertically  over  each  other 
is  a  coincidence.  It  has  nothing  to  do  with  the  leveling  problem. 
Thus  it  will  be  seen  from  the  above  that  the  two  points  from 
which  a  line  is  suspended  can  not  be  even  approximately  leveled 
by  placing  a  carpenter's  level  below  the  catenary  of  the  line  at 
its  lowest  point,  unless  the  level  is  placed  exactly  in  the  middle  of 
the  span. 


CHAPTER  VI. 

ERECTING  BUILDING  AND  MACHINERY  FOUNDATIONS. 

It  frequently  falls  to  the  lot  of  the  millwright  to  determine 
what  foundations  are  needed  to  sustain  certain  buildings  and 
machines.  At  other  times,  plans  are  sent  out  by  architects  or 
machine  builders  in  which  the  sections  of  foundations  are  laid 
down  ready  for  execution  by  the  mason  or  bricklayer.  The 
writer  has  observed  many  instances  where  the  foundations  as 
laid  down  in  the  drawings  sent  out  called  for  a  much  more 
expensive  construction  than  was  necessary.  Particularly  is  this 
true  with  plans  sent  out  by  machine  builders  where  they  include 
the  drawings  for  the  buildings  with  those  for  the  setting  of  their 
machines. 

It  is  not  my  intention  to  criticize  the  drawings  sent  out  by 
any  engineering  concern  or  any  machinery  builder,  but  such 
plans  are  usually  to  a  certain  extent  "ready-made"  or  stock  plans, 
and  are  sent  out  for  construction  in  any  soils,  ranging  from  the 
rudimentary  sandstones  of  Idaho  and  Minnesota  to  the  bogs  of 
Buffalo,  where  the  ground  shakes  for  100  feet  in  every  direction 
when  a  hammer  drops  upon  a  pile.  Drawings  intended  for  such 
universal  use  can  only  be  made  to  show  foundations  substantial 
enough  for  the  bogs  and  the  poor  soil.  These  foundations  will 
prove  wasteful  if  executed  in  soils  which  will  carry  three  and  four 
tons  to  the  square  foot.  The  man  who  makes  stock  drawings 
has  no  choice.  He  must  put  in  foundation  enough  for  the  bog 
and  let  the  sand  man  waste  his  good  money  in  useless  concrete 
work  and  masonry, 

WASTEFUL  FOUNDATION  DRAWINGS. 

Tt  is  often  the  millwright  who  must  discriminate  between 
the  demands  of  common  sense  and  the  wasteful  drawings  fur- 
nished with  the  machines  which  he  has  to  erect.  Where  drawings 
are  made  as  they  should  be,  for  the  particular  case  in  hand, 

56 


ERECTING  FOUNDATIONS 


57 


there  is  no  excuse  for  putting  in  useless  tons  of  valuable  cement 
or  thousands  of  good  bricks.  Neither  should  there  be  con- 
structed light  cinder  concrete  foundations  upon  which  heavy 
gearing  is  to  transmit  power.  Heavy  foundations  are  needed 
where  heavy  gear  teeth  are  meshing  continually  under  heavy 
loads,  and  building  foundations  adjacent  to  such  machinery  foun- 
dations also  need  to  be  heavily  constructed  of  good  material. 

It  is,  then,  up  to  the  millwright  to  prepare  himself  to  discover 
when  drawings  call  for  a  waste  of  concrete  and  brick  and  mor- 
tar, and  to  detect  weak  places  in  machinery  foundations  should 
such  weaknesses  exist.  To  do  this,  the  millwright  must  know 
something  of  the  carrying  power  of  the  different  soils,  and  he 
should  be  able  to  figure  the  strains  imparted  to  foundations  by 
moving  machinery. 

THE  LOAD-CARRYING  POWER  OF  DIFFERENT  SOILS. 

The  safe  load  which  may  be  placed  upon  any  foundation 
depends  upon  the  carrying  power  of  the  soil  and  the  area  of  the 
foundation  footing.  It  is  not  the  purpose  of  this  book  to  enter 
into  a  discussion  of  the  carrying  power  of  the  various  kinds  of 
soil  met  with,  therefore  nothing  will  be  given  in  that  direction 
save  the  following  table  which  will  serve  as  a  guide  to  the  mill- 
wright when  he  must  determine  whether  or  not  the  plans  fur- 
nished call  for  an  excessively  heavy  foundation,  or  whether  the 
mass  of  material  shown  underneath  some  heavy  machine  is 
insufficient  for  the  particular  soil  met  with  during  the  operations 
at  hand. 

TABLE  I.— BEARING  POWER  OF  SOILS. 
By  Prof.  Ira  C.  Baker,  University  of  Illinois. 


Kind  of  Material. 


Tons.  sq.  Ft. 


Min. 


Max. 


Rock — the  hardest — in  thick  layers,  in  native  bed  . . . 

Rock  equal  to  best  ashlar  masonry 

Rock  equal  to  best  brick  masonry 

Rock  equal  to  poor  brick  masonry 

Clay  on  thick  beds  (always  dry) 

Clay  on  thick  beds  (moderately  dry) 

Clay,  soft 

Gravel  and  coarse  sand,  well  cemented 

Sand ,  compact  and  well  cemented 

Sand,  clean,  dry    

Quicksand,  alluvial  soils,  etc 


200 

25 

15 

5 

4 

2 

1 

8 

4 

2 

0.5 


30 

20 

10 

6 

4 

2 

10 

6 

4 

1 


58 


MILLWRIGHTING 


SHAPE  OF  CONCRETE  FOUNDATIONS. 

Drawings  sent  out  with  machines  frequently  call  for  concrete 
foundations  with  slanting  or  taper  sides  which  call  for  very 
expensive  form  construction.  An  example  of  this  kind  is  shown 


FIG.  25.— COSTLY  TAPER  SIDE  FOUNDATION. 


by  Fig.  25,  where  a  small  square  foundation  is  made  with  taper 
sides  which  in  turn  are  surmounted  by  a  45-degree  bevel  as 
shown  at  a,  but  which  the  millwright  is  warranted  in  changing  to 
a  form  which  is  exactly  as  strong  and  which  requires  less  than 
one-tenth  the  cost  of  form  construction.  This  foundation  is 
18  feet  square  on  top  at  a,  and  is  to  carry  a  load  of  18  tons  in 
sand,  rather  loose,  as  determined  by  driving  a  bar  down  through 
it.  To  the  millwright,  the  sand  seems  safe  to  be  allotted  not  over 
two  tons  to  the  square  foot  of  surface. 

The  foundation,  as  shown  by  the  drawing,  proves  to  be  4  feet 
high,  30  inches  square  at  the  base,  and,  as  stated,  12x12  inches  at 
the  top.  To  make  a  form  for  this  shape  requires  a  form  of  con- 
struction similar  to  that  shown  by  Fig.  26,  the  plan  and  section 
views  showing  plainly  the  construction  which  involves  a  consid- 


ERECTING  FOUNDATIONS 


59 


erable  amount  of  labor  and  tight,  close-fitting  matched  boards, 
together  with  four  pieces  of  scantling  and  a  piece  at  the  top 
which  must  be  chamfered  on  both  edges. 


Section  through  A-B 


FIG.    26.— A    COSTLY  AND   TROUBLESOME    FORM. 


A  TROUBLESOME  FOUNDATION  REDESIGNED. 

This  pier  or  foundation  should  be  redesigned,  as  shown  by 
Fig.  27,  the  taper  sides  disappearing  altogether  and  the  entire 
foundation  being  formed  of  three  rectangular  blocks,  built  one 
at  a  time  on  top  of  each  other,  one  square  form  being  rammed 
full  of  cement  and  then  another  and  smaller  form  placed  on  top 
of  the  filled  one  and  rammed  in  its  turn.  In  the  redesigned  foun- 
dation, the  cube  b  is  made  tall  enough  to  reach  to  the  floor  line, 
16  inches,  and  for  the  sake  of  good  looks — not  for  strength — it  is 
made  of  the  same  length  and  width.  The  remainder  of  the  foun- 
dation, being  below  the  floor  line,  may  be  made  any  size,  but  it 


60 


MILLWRIGHTING 


should  be  just  large  enough  and  no  larger,  than  is  called  for  to 
carry  the  load  placed  upon  it. 

The  object  of  making  a  foundation  larger  at  the  bottom  is  to 
secure  bearing  enough  on  the  earth  to  safely  carry  the  load  to 
be  put  upon  it.  As  it  has  been  decided  that  the  soil  met  with 


FIG.    27.— TAPER    SIDE    FOUNDATION    REDESIGNED. 

will  safely  take  care  of  two  tons  to  the  square  foot,  there  will  be 
required  18 -r- 2=9  square  feet  of  surface  at  the  bottom  of  the 
foundation.  This  means  that  the  footing  should  be  3  feet  square, 
whereas  the  taper  side  foundation  is  only  30  inches  square, 
and  was  evidently  designed  for  soil  which  would  carry  2^  tons 
to  the  square  foot. 

TESTING  CARRYING  POWER  OF  SOILS. 

If  there  is  any  doubt  in  the  mind  of  the  millwright  as  to  the 
load  any  soil  can  safely  carry,  let  him  place  a  12xl2-inch  bearing 
on  the  soil  in  question  and  load  the  bearing  with  stones,  brick,  sand 
or  anything  weighty  until  the  little  foundation  fails  by  squeezing 
its  way  into  the  ground.  The  millwright  can  then  assume  such 
a  factor  of  safety  as  he  sees  fit,  and  determine  the  safe  carrying 
capacity  of  the  soil  under  discussion. 


ERECTING  FOUNDATIONS 
CHEAPLY  CONSTRUCTED  FORM. 


61 


But  the  redesigned  foundation  will  be  given  a  bearing  of  9 
square  feet  upon  the  sand,  and  the  intermediate  section  will  be 
made  so  as  to  give  equal  steps  back  from  the  36  to  16  inches.  As 
there  are  10  inches  on  a  side  for  the  top  block  to  fall  back,  the 
steps  must  be  5  inches  each.  Fig.  28  shows  the  simple  and  cheap 
construction  possible  when  the  form  is  made  to  fit  the  new  pier. 


Section 


I     -i 


•1 

d 


< 16-- 


FIG.  28.— CHEAP  FORM  FOR  REDESIGNED    PIER 

In  fact,  the  form  consists  merely  of  three  square  boxes,  open  top 
and  bottom,  being  simply  nailed  up  square  and  the  cleats  e  e 
nailed  on  to  hold  together  the  two  8-inch  boards  of  which  each 
side  is  composed. 

The  box  a  is  first  placed  in  position  and  filled  with  concrete, 
level  full,  then  box  b  is  laid  on  top,  and  two  bits  of  board  d  d 
nailed  on  to  keep  box  b  in  place  until  filled.  After  this  box  is 
rammed  full  of  concrete,  the  third  box  c  is  put  in  position,  cleated 


62  MILLWRIGHTING 

at  d  d  and  rammed.  With  this  form  of  construction  there  is  no 
tedious  under-ramming  as  is  necessary  with  the  form  shown  by 
Fig.  26,  where  a  surface  30x30  inches  must  be  rammed  through 
an  opening  12x12  inches. 

VIGILANCE  NECESSARY  BY  THE  MILLWRIGHT. 

This  example  is  given  not  as  a  guide  toward  the  making  of 
concrete  forms  and  the  changing  of  drawings  furnished,  but  for 
the  purpose  of  showing  the  millwright  that  it  is  necescsary  for 
him  to  be  alive  to  every  little  point  in  the  construction  of  a  mill, 
and,  being  able  to  figure  the  size  of  any  foundation,  he  can  check 
the  work  of  the  man  who  made  the  foundation  drawings,  espe- 
cially when  these  are  of  the  stock  variety,  thereby  occasionally 
saving  a  few  hundred  dollars  worth  of  cement  for  his  employer, 
and  also,  perhaps,  preventing  the  overloading  of  some  bit  of 
foundation  which  may  have  been  overlooked,  or  which  must, 
perhaps,  stand  on  ground  not  quite  as  solid  as  estimated  when 
the  foundation  drawings  were  made  up. 

The  old  adage  about  "eternal  vigilance  being  the  price  of 
liberty"  applies  particularly  well  to  the  millwright  and  his 
responsibility. 

CONCRETE  CONSTRUCTION. 

It  is  not  the  business  of  the  millwright,  or  of  this  book,  to 
design  or  teach  the  design  of  cement  construction,  yet  it  is  neces- 
sary for  the  millwright  to  understand  the  principles  of  that 
form  of  construction,  as  he  must  also  understand  the  principles 
of  wood,  masonry  and  steel  structural  work.  Plain  concrete  con- 
struction is  comparatively  simple,  and,  as  in  brick  or  stone  work, 
it  consists  of  placing  the  material  in  such  position  that  it  will 
sustain  its  own  weight  and  the  weight  which  may  be  placed  upon 
it.  In  concrete  work,  the  load  is  carried  almost  entirely  by  the 
quality  of  concrete,  which  is  measured  by  its  resistance  to 
crushing. 

The  transverse  strength  of  concrete  should  not  be  depended 
upon  to  any  extent,  neither  should  its  tensile  strength.  Bear  in 
mind  in  all  concrete  wrork,  as  in  masonry,  that  in  unsupported 
spans  the  material  must  be  so  placed  that  it  is  held  in  place  by 
its  own  weight  and  the  weight  of  any  load  which  may  be  above 


ERECTING  FOUNDATIONS  .       63 

it.  This  limits  the  use  of  concrete  to  the  arch,  the  pillar  and  the 
wall.  The  beam  cannot  be  used  without  sacrificing  economy  of 
construction  in  the  placing  of  enormous  beams  which  carry  their 
load  through,  being  to  all  intents  and  purposes  immense  solid 
arches. 

REINFORCED  CONCRETE. 

When  concrete  must  be  used  for  beams,  resource  must  be  had 
to  reinforcing  the  concrete  with  steel  sufficient  to  carry  the  ten- 
sile strains.  All  beams  are  in  compression  on  top  and  in  tension 
underneath,  hence  the  steel  and  the  concrete  are  so  disposed  as 
to  each  carry  their  own  part  of  the  load.  The  good  designer  of 
reinforced  concrete  will  reduce  the  cost  of  both  kinds  of  material 
to  the  lowest  point  by  so  designing  his  work  that  no  bit  of  con- 
crete is  in  tension,  and  no  piece  of  steel  has  any  compressive  load 
to  carry.  The  millwright  will  be  far  toward  possessing  a  working 
knowledge  of  concrete  and  reinforced  concrete  construction  when 
he  has  fixed  the  compression  and  tension  carrying  business  firmly 
in  his  understanding. 

While  tests  of  concrete  show  a  strength  in  tension  of  2,000 
to  4,000  pounds  to  the  square  inch,  this  property  of  concrete 
should,  as  stated,  be  neglected  entirely,  though  according  to 
Professor  Hatt  the  safe  working  strain  of  concrete  in  tension 
is  300  pounds  to  the  square  inch.  Concrete  in  shear  will  stand  50 
to  65  pounds  to  the  square  inch,  and  in  compression  it  ranges  from 
2,000  to  4,000  pounds  to  the  square  inch,  well  made  and  mixed 
1 :2 :4,  one  month  old.  This  would  give  a  working  value  of  500 
to  800  pounds  to  the  square  inch,  using  a  factor  of  safety  of  4. 
Cinder  concrete  is  not  as  strong.  Mixed  1 :2 :3,  it  stands  only 
about  1,000  pounds  to  the  square  inch  and  should  not  be  loaded 
to  more  than  250  pounds,  and  less  than  this  when  the  load  is 
vibratory,  as  with  running  machinery. 

The  coefficient  of  expansion  of  concrete  is  0.0000055  its  length 
for  each  degree  Fahr.  As  wrought  iron  is  0.0000068,  and  steel 
is  0.0000067,  there  never  will  be  any  trouble  from  different 
expansion  of  reinforced  concrete,  as  the  expansion  of  both  sub- 
stances is  almost  identical.  The  adhesion  of  concrete  to  steel  is 
taken  at  300  pounds  to  the  square  inch.  In  the  design  of  beams 
which  are  to  be  reinforced,  the  designer  will  do  well  to  limit  the 


64  MILLWRIGHTING 

compression  strains  to  600  pounds  to  the  square  inch,  the  diagonal 
tension  to  60  pounds  and  the  average  compression  300  pounds. 
The  steel  in  any  beam  or  other  reinforced  work  should  not  carry 
a  tension  strain  greater  than  20,000  pounds  to  the  square  inch, 
and  the  shear  should  not  be  more  than  12,000  pounds.  The  com- 
pression should  be  limited  to  10,000  pounds  in  round  bars  which 
should  not  be  used  larger  than  1  inch  in  diameter,  and  unless 
hooked  around  some  object  at  the  end  with  a  6-inch  hook,  bars 
should  have  from  30  to  50  diameters  of  length  to  develop  their 
grip;  in  other  words,  to  prevent  their  load  from  slipping  or 
pulling  them  away  from  their  union  with  the  concrete. 

PLACING  AND  REMOVING  FORMS. 

When  forms  are  placed  and  removed  in  work  under  his  super- 
vision, the  millwright  will  see  that  the  forms  are  so  made  and 
placed  that  they  will  admit  of  no  settling  whatever,  which  would 
break  the  adhesion  between  the  cement  and  the  steel  before  the 
setting  of  the  former.  In  removing  the  forms  from  work,  ten 
days  should  elapse  before  they  are  removed  from  the  sides  and 
top  of  beams,  and  no  less  than  four  weeks  from  the  bottom  of 
beams  and  girders.  The  shoring  should  be  allowed  to  remain 
that  length  of  time,  and  in  very  long  beams  and  in  slabs  the 
shoring  should  be  kept  in  position  for  six  weeks  after  the  work 
was  poured. 

TESTING  CEMENT  AND  AGGREGATES. 

Although  cement  working,  like  electrical  working,  is  a  spe- 
cialty by  itself  and  is  usually  performed  by  specialists  trained  in 
the  crafts  in  question,  the  millwright  is  necessarily  such  a  "jack 
of  all  trades"  that  he  must  know  something  of  each,  and  he  must 
in  any  case,  as  he  has  to  supervise  the  construction  of  consider- 
able concrete  work,  be  informed  of  the  methods  of  testing  the 
materials  used  in  concrete  work.  It  is  usual  to  speak  of  concrete 
as  being  composed  of  "cement,  sand  and  aggregates,"  while 
other  workers  include  the  sand  with  the  stone  or  gravel  and  say, 
"cement  and  aggregate,"  "aggregate"  meaning,  usually,  broken 
rock  or  gravel. 

Cement  may  be  subjected  to  several  physical  tests  which  will 
tell  the  millwright  whether  that  particular  cement  is  or  is  not  fit 


ERECTING  FOUNDATIONS  65 

for  use  in  concrete  construction.  The  first  test,  according  to  the 
requirements  of  the  American  Society  of  Civil  Engineers,  is  that 
of  fineness. 

TEST  FOR  FINENESS. 

The  cement  having  been  properly  sampled,  being  taken  from 
a  barrel  through  a  hole  in  the  middle  of  one  of  the  staves  by 
means  of  an  augur  or  a  testing  spoon;  or,  if  in  bags,  the  sample 
is  to  be  taken  from  surface  to  center,  and  sifted  through  a  sieve 
of  20  meshes  to  the  linear  inch  to  break  up  the  lumps  and  remove 
foreign  material,  a  quantity  of  the  cement  is  weighed  and  placed 
in  a  sieve  having  200  meshes  to  the  linear  inch,  and  after  having 
been  dried  at  212  degrees  Fahr.,  if  necessary,  the  sifting  is  accom- 
plished by  placing  a  pan  under  the  sieve,  a  cover  on  top,  and  then 
shaking  the  sieve,  patting  it  at  the  rate  of  200  times  a  minute 
with  one  hand  to  help  pass  the  cement  through  the  very  fine 
wire  cloth  of  the  sieve.  The  shaking  is  to  be  continued  until  not 
more  than  1  per  cent,  passes  through  after  one  minute  of  contin- 
uous shaking.  Some  large  shot  added  to  the  cement  in  the  screen 
will  hasten  the  screening  of  the  quantity  which  is  usually  taken 
at  50  or  100  grams  (1.76  or  3.52  ounces). 

The  cement  which  does  not  pass  the  200  sieve  is  weighed  and 
not  more  than  25  per  cent,  of  the  weight  of  the  cement  should  thus 
be  rejected  by  the  No.  200  sieve.  The  residue  left  on  the  No.  200 
sieve  should  be  placed  on  the  No.  100  sieve  and  the  residue 
there  should  not  be  more  than  8  per  cent,  of  the  total  weight  of 
the  sample.  Cements  which  leave  more  than  25  per  cent,  of 
No.  200,  and  more  than  8  per  cent,  on  No.  100  sieves,  should  be 
rejected.  The  above  applies  to  portland  cement.  Natural  cement 
should  be  rejected  if  more  than  30  and  10  per  cent,  respectively, 
fail  to  pass  the  No.  200  and  the  No.  100  sieves,  but  as  natural 
cement  is  much  weaker  than  portland  cement,  it  is  not  much  used 
by  engineers  at  present. 

TESTS  FOR  CONSTANCY  OF  VOLUME. 

The  millwright  will  not  be  able  to  make  tests  for  tensile 
strength,  but  he  can  make  those  for  constancy  of  volume,  and  for 
that  purpose  he  will  make  up  little  pats  of  cement,  three  inches 
in  diameter  and  half  an  inch  thick  in  the  middle,  tapering  down 


66 


MILLWRIGHTING 


to  a  thin  edge  all  around  as  shown  by  Fig.  29.  These  pats  may 
best  be  made  by  mixing  the  cement  and  placing  it  on  pieces  of 
glass,  patting  it  down  to  the  shape  described  above. 

These  pats  are  kept  in  moist  air  for  24  hours,  being  placed  in 


Section 


Plan 

FIG.  29.— CEMENT  PAT  FOR  CONSTANCY  OF  VOLUME  TEST. 

a  box  containing  a  wet  sponge  or  wet  paper,  and  the  box  covered 
with  a  wet  cloth  which  is  to  be  kept  wet.  The  pats  should  all  be 
firm  and  hard  at  the  end  of  that  time  and  show  no  signs  of  curling 
up  from  the  glass,  or  of  checking  or  cracking,  or  of  crumbling. 
Three  pats  should  be  made  as  above;  then,  after  the  24  hours  in 
moist  air,  one  pat  should  be  laid  aside  in  air,  another  immersed 
in  water  at  about  70  degrees,  and  the  condition  of  both  pats 
observed  daily  for  28  days. 

THE  ACCELERATED  TEST  FOR  CEMENT. 

But  it  requires  too  much  time  to  make  tests  of  this  kind,  there- 
fore there  has  been  devised  what  is  known  as  the  accelerated  test, 


ERECTING  FOUNDATIONS  67 

whereby  the  condition  of  the  cement  may  be  rapidly  determined 
if  it  passes  satisfactorily  the  24-hour  test  in  moist  air.  Two  of  the 
three  pats  made  for  the  tests  have  been  disposed  of.  The  third 
pat  is  for  the  accelerated  test,  and  that  pat  is  placed  in  steam 
escaping  from  boiling  water  for  five  hours,  being  placed  just 
above  the  boiling  water  and  loosely  covered  for  the  time 
mentioned. 

If  the  cement  passes  the  boiling  or  accelerating  test,  it  may, 
in  addition  to  having  passed  the  fineness  test,  be  accepted,  but 
if  it  fails  to  pass  the  boiling  test,  it  should  be  held  to  be  tested 
for  tensile  strength,  a  portion  of  the  cement  being  sent  to  a 
laboratory  for  that  purpose,  where  it  is  made  up  into  briquettes 
having  a  middle  section  of  one  square  inch.  These  briquettes  are 
made  and  placed  in  moist  air  the  same  as  the  pats,  then  they  are 
put  into  air  and  into  water  in  the  manner  also  described  for  pats. 
Three  of  these  are  also  made,  and  one  is  broken  at  the  end  of  24 
hours,  the  other  after  7  days,  and  the  other  is  kept  for  28  days 
before  it  is  pulled  apart  in  a  testing  machine. 

TENSILE  STRENGTH  TESTS. 

In  addition  to  the  three  briquettes  above  described,  three  more 
briquettes  are  made  at  the  same  time,  but  consisting  of  one  part 
cement,  three  parts  sand,  and  broken  at  the  ends  of  the  times 
specified  for  the  neat  cement  briquettes.  The  result  of  the  break- 
ing tests  should  be  as  follows : 

Age  PORTLAND,  NEAT  CEMENT  Strength,  Ibs. 

24  hours  in  moist  air 150-200 

7  days  (1  day  in  moist  air,  6  days  in  water) 450-550 

28  days  (1  day  in  moist  air,  27  days  in  water) 550-650 

ONE  PART  CEMENT,  THREE  PARTS  SAND. 

7  days  (1  day  in  moist  air,  6  days  in  water) 150-200 

28  days  (1  day  in  moist  air,  27  days  in  water) 200-300 

NATURAL,    NEAT    CEMENT. 

24  hours  in  moist  air 50-100 

7  days  (1  day  in  moist  air,  6  days  in  water) 100-200 

28  days  (1  day  in  moist  air,  27  days  in  water) 200-300 

ONE  PART  CEMENT,  THREE  PARTS  SAND. 

7  days  (1  day  in  moist  air,  6  days  in  water) 25-  75 

28  days  (1  day  in  moist  air,  27  days  in  water) 75-150 

Cements  which  do  not  pass  the  fineness  and  the  pat  tests, 
should  be  treated  as  above,  and  accepted  if  they  pass  the  28-day 


68  MILLWRIGHTING 

tests.  Some  cements  fail  under  the  24-hour  tests  and  even  the 
7-day  tests,  but  pass  the  28-day  tests  successfully.  These  are  evi- 
dently slow  setting  cements,  showing  that  it  is  not  just  to  pass 
snap  judgment  upon  cements  of  any  kind. 

There  are  other  tests,  those  of  the  time  of  setting  and  the 
weight  to  the  cubic  feet,  or  specific  gravity,  which  shall  be  as 
follows,  to  have  the  cement  accepted : 

SPECIFIC  GRAVITY  AND  TIME  OF  SETTING. 

Portland  Cement. — Dried  at  212 ;  sp.gr.  3.10 ;  time  of  set,  initial, 

in  not  less  than  30  minutes,  but  must  develop  hard  set  in 

not  less  than  one  hour  nor  more  than  ten  hours. 

Natural  Cement. — Dried  at  212 ;  sp.gr.  2.8  ;  time  of  set,  initial,  in 

not  less  than  ten  minutes  and  hard  set  in  not  less  than 

thirty  minutes  nor  more  than  three  hours. 

The  specific  gravity  may  be  ascertained  by  weighing  with  the 

same  scale  used  in  determining  the  fineness  of  the  cement.    If  the 

millwright  finds  that  he  is  to  have  much  to  do  with  concrete,  it 

will  pay  him  to  procure  a  little  scale  for  cement  weighing  and 

testing.     The  necessary  screens,  together  with  the  scale,  can  be 

purchased  from  dealers  in  cement  testing  apparatus.     If  only  an 

isolated  test  or  so  has  to  be  made,  the  millwright  can  possibly 

get  the  necessary  weighing  done  by  an  apothecary  who  will  be 

fitted  with  the  necessary  scales  for  fine  weighing. 

SAND  AND  CEMENT  TESTING  SCREENS. 

In  any  case,  the  millwright  should  have  a  few  screens  for 
testing  not  only  cement  but  sand  as  well.  Nos.  100  and  200  mesh 
are  used  as  noted  above  for  cement,  and  standard  sand  is  that 
which  is  caught  on  No.  30  mesh  after  passing  through  No.  20. 
The  millwright  should  have  these  screens  also,  and  if  there  is  any 
likelihood  of  having  to  do  with  cement  block  construction  and 
sand-lime  factory  construction  and  operation,  then  there  will 
be  needed  screens  Nos.  2,  4,  8,  12,  16,  20,  40,  60,  80,  100,  120  and 
150.  These,  together  with  those  mentioned  for  sand  and  for 
cement,  will  make  a  nest  of  16  sieves,  ranging  from  2  to  200 
meshes  to  the  linear  inch.  These,  with  cover  and  pan,  will  cost 
about  $25.  The  scale  will  cost  about  $10  more. 


ERECTING  FOUNDATIONS  69 

HOME-MADE  TESTING  SIEVES. 

If  preferred,  pieces  of  wire  cloth  of  the  grades  mentioned, 
8x8  inches  may  be  purchased  for  about  $10,  and  the  millwright 
may  have  the  tin  rims  made  up  by  the  local  plumber.  This  course 
was  followed  by  the  writer,  who  has  for  his  own  use  a  set  of  sieves 
of  the  numbers  mentioned  which  were  made  up  at  home  at  a  cost 
of  (excepting  time)  about  $14. 

TESTING  THE  SPECIFIC  GRAVITY. 

It  will  be  very  easy  for  the  millwright,  perhaps  with  the  aid  of 
a  friendly  druggist,  to  ascertain  the  specific  gravity  of  cement. 
To  do  so,  weigh  out  a  convenient  quantity  of  cement,  first  having 
dried  it  at  212  as  elsewhere  directed.  Then  procure  a  bottle 
which  will  hold  about  three  times  the  quantity  of  the  cement 
weighed  out.  Fill  the  bottle  with  water  as  close  to  60  degrees 
temperature  as  possible,  and  procure  another  vessel,  either  a  bottle 
or  a  pitcher,  from  which  the  water  may  be  easily  poured  into  the 
bottle.  Carefully  weigh  the  second  vessel  and  mark  its  weight 
for  future  reference. 

If  the  millwright  have  at  his  command  a  very  fine  scale  weigh- 
ing down  to  1/100  of  an  ounce,  then  he  may  make  the  test  with 
a  single  ounce  of  cement,  but  if  coarser  scales  must  be  used,  then 
the  quantity  of  cement  should  be  increased.  That  is  what  is 
meant  by  a  "convenient  quantity"  of  cement  which  was  to  be 
weighed  out.  Having  carefully  weighed  the  second  vessel,  fill 
the  first  one — the  bottle  with  a  small  neck — even  full  of  water  as 
described,  then  pour  a  portion  of  the  water,  say  one  half,  into  the 
second  vessel,  taking  care  not  to  lose  a  drop  of  the  water  in  any 
of  the  operations. 

Next,  introduce  the  weighed  quantity  of  cement  through  the 
narrow  neck  of  the  half  filled  bottle,  and  shake  enough  to  get  all 
the  cement  fully  wet  and  to  make  sure  that  no  air  bubbles  remain 
under  water.  Fill  the  bottle  again,  with  water  from  the  second 
vessel,  taking  great  care  to  fill  the  bottle  even  full  without  losing 
a  single  drop  of  the  water.  There  will  be  some  water  left  in  the 
second  vessel,  which  must  be  weighed  again  with  that  water  in 
it  and  the  weight  of  the  water  found  by  deducting  the  weight  of 
the  empty  vessel  from  the  weight  of  the  vessel  and  the  left-over 
water.  The  result  will  be  the  weight  of  a  mass  of  water  having 


70  MILLWRIGHTING 

the  same  bulk  as  the  known  quantity  of  cement  placed  in  the  bot- 
tle. Divide  the  weight  of  the  water  displaced  from  the  bottle 
by  the  cement,  and  the  quotient  will  be  the  specific  gravity.  Mul- 
tiply the  weight  of  a  cubic  foot  of  water  (62.5  Ibs.)  by  the  specific 
gravity  and  the  product  will  be  the  weight  of  the  cement  to  the 
cubic  foot. 

Before  placing  the  cement  in  the  bottle  with  the  water,  should 
the  millwright  carefully  measure  the  space  occupied  by  the  cement, 
by  packing  it  carefully  into  a  box  or  cylinder  of  known  dimen- 
sions, then,  if  the  bulk  measurement  of  the  displaced  water,  be 
divided  by  the  bulk  measurement  of  the  cement,  the  result  will  be 
the  percentage  of  solid  matter  in  the  cement.  Substract  the  per- 
centage thus  found  from  100  and  the  result  will  be  the  percentage 
of  voids  in  the  cement,  which  well  shaken  down  into  the  measur- 
ing vessel,  will  range  from  30  to  50  per  cent. 

THE  USE  OF  OIL  FOR  GRAVITY  DETERMINATION. 

The  density  test  for  cement  described  above,  although  accurate 
enough  for  the  rough  work  required  by  the  millwright,  is  not 
correct,  owing  to  the  possibility  that  some  of  the  lime  present 
may  be  hydrated  when  in  contact  with  the  water.  To  make  this 
test  correct  enough  for  scientific  purposes,  kerosene  oil  should  be 
used  instead  of  water  for  filling  the  bottle  described  above.  The 
work  is  the  same  except  that  to  obtain  the  weight  to  the  cubic  foot 
the  specific  gravity  must  be  multiplied  by  the  weight  of  a  cubic 
foot  of  kerosene  oil.  That  substance  having  a  specific  gravity 
of  about  .7  to  .8,  it  is  necessary  to  calculate  the  weights  to  the 
cubic  foot  accordingly. 

For  instance :  at  a  specific  gravity  of  .7,  the  weight  to  the  cubic 
foot  of  the  oil  would  be  .7x62.5=43.75  pounds  to  the  cubic  foot 
and  for  other  densities  in  proportion.  It  is  recommended  that 
naphtha  having  a  sp.gr.  of  .729  be  used  for  this  test.  When  such 
a  light  oil  is  used,  care  must  be  taken  to  prevent  error  through  a 
portion  of  the  oil  volatizing  between  the  times  it  is  weighed.  A 
very  interesting  exhibit  can  be  made  of  the  cement  in  the  naphtha 
if  the  mixture  be  placed  in  a  tall  thin  bottle  or  tube  and  well 
shaken,  then  allowed  to  settle.  It  will  be  found  that  the  cement 
is  graded  in  the  tube,  the  heavier  and  coarser  portions  going  to 
the  bottom,  the  finer  particles  next,  and  so  on  to  the  top  of  the 


ERECTING  FOUNDATIONS  71 

mixture,  where,  if  there  be  a  deposit  of  yellow  substance,  it  indi- 
cates the  presence  of  under-burned  material  in  the  cement.  This 
test  applies  more  particularly  to  portland  cement. 

BROKEN  STONE  AND  SAND. 

In  the  making  of  concrete,  after  having  proved  that  the 
cement  will  pass  inspection,  the  millwright  should  see  that  no 
decayed  or  very  soft  rock  is  used  in  crushing  the  aggregate.  The 
strength  of  concrete  is  only  that  of  the  rock  of  which  it  is  made, 
and  if  rotten  shale  be  used,  either  in  the  form  of  broken  stone  or 
as  gravel,  a  weak  concrete  can  be  the  only  result. 

.  If  there  is  a  chance  that  the  concrete  will  be  exposed  to  fire, 
limestone  rock  should  be  avoided,  and  he  also  should  avoid  feld- 
spar for  the  same  reasons.  See  that  the  rock  breaks  square  and 
clean  and  is  not  crushed  so  that  it  crumbles  under  the  fingers. 
Some  rock,  particularly  granite,  is  apt  to  break  in  this  manner 
and  the  concrete  is  weakened  thereby. 

USE  WELL  SCREENED  ROCK  AND  SAND. 

•  Although  sand  and  rock  are  to  be  used  in  concrete,  it  is  not 
well  to  allow  them  to  come  together  before  they  arrive  at  the 
mixing  table  or  machine.  If  mixing  be  allowed  in  the  bin,  some 
portions  of  the  concrete  will  have  more  fines  than  other  portions 
and  it  is  impossible  to  judge  the  proportions  met  with  in  different 
portions  of  the  same  bin,  hence  it  is  impossible  to  make  uniform 
concrete  from  material  mixed  in  the  bins. 

PROPORTIONING  ROCK  AND  SAND. 

It  should  be  the  business  of  the  millwright  to  see  that  the 
proportions  of  rock,  sand  and  cement  used  are  fitted  to  the  pecu- 
liarities of  the  material  to  be  at  hand.  Let  him  make  some  experi- 
ments with  the  material  actually  being  used  on  the  work.  Con- 
struct a  square  box,  12  inches  inside  measurement,  with  tight  bot- 
tom but  no  top.  Weigh  this  box  carefully  and  fill  it  with  the 
broken  rock,  shaken  down  as  closely  as  possible,  and  weigh  accu- 
rately. Shake  out  the  broken  rock  and  mix  with  it  a  certain  pro- 
portion of  smaller  broken  stone  or  gravel.  Add  a  small  quantity 
at  a  time  and  replace  in  the  cubical  box.  Note  the  amount  of  fine 
stone  which  may  be  added  without  increasing  the  volume  of  the 
broken  stone. 


72  MILLWRIGHTING 

Having  determined  the  above  point,  weigh  the  contents  of 
the  box  and  note  the  increase  in  weight  to  the  cubic  foot  caused 
by  rilling  the  voids  with  smaller  pieces  of  broken  stone.  Next, 
repeat  the  operations,  this  time  using  sand  which  is  mixed  with 
the  coarse  and  fine  rock  and  replaced  in  the  cubical  box.  When 
the  point  is  arrived  at  which  gives  the  heaviest  weight  to  the 
foot,  the  mixture  then  contained  in  the  box  is  the  one  which  the 
millwright  should  seek  to  maintain  continually. 

PROPORTIONS  OF  CEMENT  AND  WATER. 

The  desired  proportion  of  cement  may  then  be  added  to  the 
contents  of  the  box,  and  that  percentage  of  cement  which  can 
be  added  to  the  box  without  increasing  the  volume  of  the  contents, 
will  prove  the  quantity  best  adapted  to  the  materials  being  used 
for  that  particular  concrete. 

Finally,  the  box  may  be  emptied  again,  and  the  water  added, 
experiments  being  made  to  determine  exactly  how  much  liquid 
will  be  required  to  so  temper  the  concrete  that  it  will  tamp  into 
the  box  and  barely  show  water  on  the  surface  of  each  tamped 
layer.  The  millwright  will  have  opportunity  to  note  the  smaller 
or  larger  volume  of  the  concrete  when  it  has  been  gaged  and 
tamped,  and  the  quantity  of  water  necessary,  as  determined  above, 
should  be  carefully  maintained  through  all  the  work. 

STANDARD  SAND. 

In  testing  cement,  especially  in  making  briquettes,  there  is 
used  what  is  known  as  ''standard  sand."  The  engineer  or  chemist 
has  this  sand  at  hand  in  quantities,  and  it  is  usually  made  from 
grinding  and  crushing  quartz  rock  or  some  other  material,  almost 
pure  silica.  Sand  obtained  in  different  grades  by  sifting  natural 
sand  is  not  uniformly  silicious,  as  Lake  Erie  sand,  for  example, 
shows  mostly  shale  in  the  coarser  grades,  silica  in  the  medium 
grades,  and  the  No.  'SO  contains  a  large  number  of  garnets, 
while  No.  100  is  largely  of  heavy  black  sand.  Hence  in  obtaining 
sand  for  any  course  of  experiments,  care  must  be  taken  to  obtain 
that  either  crushed  from  quartz  or  obtained  from  a  natural  deposit 
in  which  the  various  grades  are  of  the  same  character.  At 
Ottawa,  111.,  is  a  deposit  of  natural  sand  which  fills  the  conditions, 
and  The  Sandusky  (O.)  Portland  Cement  Company  has  agreed 


ERECTING  FOUNDATIONS  73 

to  undertake  the  preparation  of  this  sand  and  to  furnish  it  at  a 
price  only  sufficient  to  cover  the  actual  cost  of  preparation. 

GRADING  SAND. 

Sand  caught  between  sieves  Nos.  20  and  30  is  at  present 
the  recognized  standard  for  making  up  cement  mortars  for  test 
and  for  comparison,  but  it  is  an  open  question  as  to  what  grade 
of  sand  makes  the  strongest  mortar.  A  sand  much  finer  than 
No.  20,  intimately  mixed  with  the  cement  in  proportion  to  fill  the 
voids  in  the  No.  20  sand,  will  yield  a  much  stronger  mortar  than 
the  No.  20  sand  alone.  It  is  the  same  old  story  of  filling  the  voids, 
for  No.  20  sand  contains  as  much  void  space  as  does  the  broken 
stone,  and  it  is  only  a  question  of  the  proper  mixing  of  the  various 
grades  of  sand  in  order  to  obtain  the  strongest  mortar. 

Sand  for  mortar  may  contain  every  size  which  will  pass 
through  a  No.  4  sieve,  but  it  may  be  graded  in  the  same  manner 
as  the  rock  and  gravel  was  handled  and  give  better  results.  In 
fact,  the  same  apparatus  may  be  used,  the  addition  of  the  grading 
sieves  being  all  the  extra  utensils  necessary,  though  it  will  doubt- 
less be  found  better  to  use  a  smaller  unit  than  a  cubic  foot  on 
account  of  the  labor  of  screening  such  large  quantities  of  sand. 
A  box,  3-inch  cube,  and  containing  1/64  foot,  will  answer  very 
well  for  grading  sands  for  mortar  purposes. 

PROPORTIONING  CEMENT,  SAND  AND  BROKEN  STONE  FOR 
CONCRETE. 

The  time-honored  rule  is : 
Cement.   Sand.     Stone. 

123     for  machine  foundations. 

1  2  5    )  r      ,    .,,.        ,        -  ^ 

"    i         building  foundations. 

Recent  advance  in  concrete  proportioning  has  demonstrated 
that  these  rules  are  far  from  accurate,  and  that  the  quantity  of 
cement  and  sand  cannot  be  determined  by  any  empirical  formula, 
but  must  be  determined  from  actual  tests  of  the  cement,  sand 
and  broken  stone  or  gravel.  But  in  49  instances  out  of  50,  the 
1-2-3,  and  1-2-5  rules  call  for  too  much  sand  and  cement,  and  not 
enough  gravel,  when  the  smaller  sizes  of  rock,  say  %-mch,  be 
used. 


74  MILLWRIGHTING 

The  sand  may  be  tested  as  noted  in  chapter  VI,  page  68,  and 
it  will  be  found  that  if  the  sand  is  screened  between  No.  16  and 
No.  20  sieves,  and  the  gravel  caught  between  No.  2  and  No.  4 
sieves,  concrete  made  of  these  materials  and  mixed  1-1-4  will  be 
stronger  than  any  concrete  you  ever  saw  before,  and  that  it  will 
not  soak  up  more  than  6  per  cent,  of  water.  The  larger  the 
broken  stone  or  gravel,  the  less  sand  and  cement  will  be  neces- 
sary in  order  to  proportion  a  strong  and  impervious  concrete,  and 
the  millwright  can  put  in  a  little  profitable  study  in  this  direction. 
A  very  coarse  gravel  makes  a  most  excellent  cement  without  the 
addition  of  sand,  or  a  very  little.  Usually  none  will  be  required, 
and  often  some  sand  can  be  screened  out  of  the  gravel  to  advan- 
tage, the  strength  of  the  resulting  concrete  being  increased 
thereby. 

A  SCIENTIFIC  METHOD  OF  PROPORTIONING  CONCRETE. 

The  author  has  succeeded  in  working  out,  after  months  of 
experiment,  a  method  of  proportioning  concrete  which  removes 
entirely  the  element  of  guesswork,  and  enables  the  inexperienced 
concrete  worker  to  mix  or  to  proportion  the  ingredients  for  a 
batch  equally  as  well  as  the  man  who  has  worked  a  lifetime  mak- 
ing concrete.  In  fact,  by  following  the  directions  given,  a  novice 
can  proportion  concrete  far  better  with  the  method  than  the  most 
experienced  man  can  do  without  the  method  in  question.  When 
using  the  method  described  below,  it  does  not  matter  whether  or 
not  the  workman  has  ever  had  experience  with  the  particular 
material  to  be  used.  It  does  not  matter  whether  he  is  to  use  bank 
gravel  or  stone  screenings.  In  either  case,  ,there  can  be  obtained 
from  the  material  at  hand  the  very  best  results  possible. 

CURVES  FOR  PROPORTIONING  CONCRETE. 

Prepare  a  chart,  or  curve  diagram,  upon  as  large  a  scale  as 
desired,  similar  to  that  shown  by  Fig.  29-a,  the  vertical  distance  to 
be  divided  into  100  parts  and  each  of  these  parts  is  taken  as  1 
per  cent,  of  the  volume  of  any  mixture  for  making  concrete. 
Divide  the  horizontal  line,  at  the  top,  into  equal  portions  of  an 
inch,  the  figures  at  the  top  indicating,  respectively,  5/300,  10/100 
and  15/100  inch,  etc.  The  curve  A  is  the  one  for  concrete 
made  from  1-inch  broken  stone.  The  curve  B  is  for  concrete 


ERECTING  FOUNDATIONS 


75 


containing  %-inch  broken  stone  or  gravel  as  the  largest 
material  used.  The  curve  C  is  for  use  when  2-inch  broken  stone 
is  to  be  used. 

It  will  be  noted  that  curve  A  "runs  ashore"  at  the  point  of 
intersection  between  the  100  per  cent,  line  and  the  vertical  line 
indicating  material  with  a  diameter  of  one  inch.  In  like  manner 
the  curve  B,  for  %-inch  rock  or  gravel,  runs  ashore  at  0.442 


8.      S      S      55      8      3 


S       3     § 


100 
95 
90 
85 
80 
75 
70 
65 
60 
a  55 
o50 

40 
35 

30 
25 
20 
15 
10 
5 
0 


FIG.  29-a.— CURVES  FOR  PROPORTIONING  CONCRETE. 

inches  from  the  zero  line.  This  diameter  represents  the  size  of 
material  which  will  pass  through  a  No.  2  sieve,  the  difference 
between  0.442  and  0.5  being  the  diameter  of  the  wire  used  in 
making  a  %-inch  sieve.  For  determining  the  curve  of  the  2-inch 
stone,  the  chart  must  be  continued  to  the  right  until  the  2-inch  dis- 
tance is  reached,  obviously  just  twice  the  length  of  the  1-inch 
chart. 

LAYING  OUT  A  CONCRETE  CHART. 

The  how  and  why  of  this  chart  cannot  be  discussed  here 
from  lack  of  space,  and  it  must  suffice  to  say  that  the  author 
has  proved  to  his  own  satisfaction,  by  repeated  tests  of  blocks 
made  according  to  the  various  curves  and  tested  to  destruction 
in  a  compression  recording  machine,  that  the  curve  is  so  nearly 
correct  that  he  is  unable  to  determine  in  which  direction  the  curve 


76  MILLWRIGHTING 

should  be  changed  to  improve  the  quality  of  the  concrete  made 
from  it. 

Having  drawn  to  scale,  and  divided  as  shown  by  Fig.  29-a 
the  lines  0-100  and  100-1.00  inches,  place  a  ruler  upon  points 
0  and  .95,  and  cut  the  95  per  cent,  line  at  a.  This  is  one  point  in 
the  curve  A.  Next,  place  the  ruler  on  0  and  .90  inches,  and 
mark  the  90  per  cent,  line  at  b.  This  is  another  point  in  curve  A. 
Proceed  in  a  similar  manner  from  0  to  .85,  .80,  .75  inches,  etc., 
obtaining  points  c,  d.  etc.,  one  upon  each  of  the  5  per  cent,  lines. 
When  these  points  are  all  connected  by  a  line,  the  curve  A  is 
obtained. 

To  draw  curve  B,  for  No.  2  gravel  or  stone,  locate  the  .442- 
inch  point  on  the  upper  line,  and  consider  that  point  as  100  and 
divide  the  distance  from  the  per  cent,  line  (.442  inch)  again 
into  100  equal  parts,  marking  each  five  of  these  parts  as  before, 
and  again  drawing  lines  from  each  five-point  mark  to  0.  The 
points  where  these  new  lines  cut  the  percentage  lines  at  e,  f,  g, 
etc.,  will  be  points  in  the  new  %-inch  curve  B,  and  a  line  drawn 
through  all  the  points  in  question  will  give  the  curve  as  shown 
by  Fig.  29-a.  Curve  C  is  found  in  a  similar  manner,  laying  off 
2  inches  on  the  upper  line,  dividing  the  laid-off  distance  into  100 
parts  in  groups  of  five  parts  each,  and  then  drawing  lines  to  0, 
as  before. 

Along  the  lower  edge  of  the  chart  are  laid  off  the  screen  or 
sieve  numbers,  1,  2,  4,  etc.  In  order  to  lay  down  these  lines  it  is 
necessary  to  ascertain  the  size  of  the  holes  in  each  of  the  sieves 
or  screens  used.  Each  set  of  sieves  must  be  figured  separately. 
What  is  right  for  one  make  may  be  wrong  for  another.  The 
sieves  used  by  the  author,  described  on  page  68  of  this  chapter, 
have  the  following  mesh  openings : 

No.    2,  0.442  inch.  No.     50,  0.011  inch. 

4,  0.221  "  "       60,  0.009     " 

"       8,  0.066  "  "       80,  0.007     " 

"     12,  0.060  "  "  100,  0.0045  " 

"     16,  0.042  "  "  120,  0.0038  " 

"     20,  0.034  "  "  150,  0.0032  " 

"     30,  0.022  "  "  200,  0.0026  "       • 

"     40,  0.015  " 

These  diameters  will  be  laid  off  at  the  top  of  the  chart,  begin- 
ning at  No.  50  sieve=0.011  inch  in  diameter.  The  vertical  line 


ERECTING  FOUNDATIONS  77 

representing  No.  50  sieve,  it  will  be  noted,  comes  very  close  to 
the  percentage  line — only  eleven  thousandths  of  an  inch  from  that 
line,  and  the  space  between  these  two  lines  will  be  regarded  as 
filled  with  cement.  On  page  65  of  this  chapter  it  was  noted 
that  no  more  than  8  and  25  per  cent,  of  the  cement  should  fail  to 
pass  the  Nos.  100  and  200  sieves.  The  coarse  portion  of  the 
cement  runs  down  to  about  No.  50  mesh,  and  in  the  diagram 
all  that  portion  of  the  curve  to  the  left  of  the  No.  50  sieve  line 
may  be  regarded  as  filled  with  cement  up  to  the  curve  correspond- 
ing to  the  size  of  stone  to  be  used. 

Thus,  it  will  be  noted  that  the  A-curve  crosses  the  No.  50  sieve 
line  at  about  12  per  cent.  The  B-curve  crosses  at  about  18  per 
cent.,  while  the  C-curve  crosses  somewhere  about  9  per  cent.  It 
is  for  accurately  determining  these  intersections  that  the  curves 
should  be  drawn  to  as  large  a  scale  as  possible — or  convenient. 
The  intersections  noted  above  were  taken  from  a  large  chart,  not 
from  the  small  one  shown  by  Fig.  29-a.  Here  will  be  noted  the 
first  peculiarity :  that  2-inch  rock  requires  only  one-half  as  much 
cement  as  i^-inch  rock ;  hence,  every  time  the  size  of  the  stone  is 
quartered,  the  amount  of  cement  must  be  doubled. 

To  DETERMINE  THE  NECESSARY  QUANTITY  OF  SAND. 

Taking  curve  A  for  1-inch  broken  stone,  we  have  found  that 
12  per  cent,  of  cement  should  be  used  with  this  size  of  rock.  For 
convenience,  we  will  call  it  12%  per  cent.,  or  one-eighth  of  the 
total  weight  of  concrete,  leaving  seven  parts  to  be  apportioned 
among  the  various  sizes  of  sand  and  stone  1  inch  or  smaller  in 
diameter.  Let  it  be  understood  that  a  quantity  of  gravel  or  broken 
stone  is  available,  and  this  material  will  all  be  caught  on  the  No.  2 
screen.  The  A-curve  cuts  the  No.  2  line  at  about  66  per  cent., 
therefore  the  distance  above  that  point,  34  per  cent.,  should  be 
filled  with  1-inch  broken  stone.  This  is  nearly  but  not  quite  three 
times  the  amount  of  cement. 

But  we  must  use  some  of  the  No.  2  stone  or  gravel,  and  that 
size  can  be  put  in  until  it  reaches  down  the  curve  to  some  point 
where  it  meets  the  size  of  sand  available.  If  there  is  a  lot  of  No.  8 
sand  in  the  gravel,  the  No.  2  may  be  stopped  off  at  the  inter- 
section of  curve  A  with  the  No.  8  sieve  line,  or  at  about  32  per 
cent.  This  calls  for  the  difference  between  66  and  32=34  per 


78  MILLWRIGHTING 

cent,  to  be  composed  of  coarse  No.  2  rock  or  gravel.  There  now 
remains  32 — 12=20  per  cent,  of  sand  between  Nos.  8  and  50 
sizes.  If  we  have  plenty  of  No.  20  mortar  sand,  we  can  put  in 
32 — 17  (on  No.  20)  =15  per  cent,  of  the  coarse  sand,  No.  8,  and 
leave  the  remaining  17 — 12=5  per  cent,  to  be  filled  with  fine  sand, 
No.  20. 

It  is  shown,  therefore,  that  a  good  concrete  can  be  made  as 
follows : 

Cement 12  per  cent. 

Sand,     No.  20 5     "       " 

Sand,       "       8 15     "       " 

Gravel,    "       2 34     " 

Rock,  1 34 

But  any  number  of  variations  may  be  made  and  still  secure 
a  good  concrete.  For  instance :  were  there  available  only  No.  1 
broken  stone  and  No.  4  gravel,  a  good  concrete  could  be  made 
without  a  bit  of  fine  sand,  though  a  portion  of  the  No.  4  could  be 
replaced  by  finer  sand  and  the  strength  of  the  concrete  slightly 
increased  thereby.  The  dotted  line  d  shows  the  No.  1  and  No.  4 
combination,  the  1-inch  rock  coming  down  to  about  53  per  cent., 
the  No.  4  extending  clear  down  to  the  12  per  cent.,  or  cement  line. 
This  gives : 

Cement   12  per  cent. 

No.  4  sand 41     "       " 

No.  Irock 47     "       " 

or,  about  1  to  3i/>  and  4  parts. 

PROPORTIONS  WILL  NOT  WORK  WITH  OTHER  SIZES. 

But  these  proportions  of  fine  and  coarse  material  will  not  work 
with  other  sizes  than  1-inch  stone.  When  the  size  of  the  broken 
stone  increases,  the  percentage  of  fines  must  decrease — that  is,  of 
the  fines  below  No.  8  and  No.  12.  Contrariwise,  as  the  diameter 
of  the  largest  aggregate  used  is  diminished  in  size,  so  must  the 
quantity  of  fines  and  of  cement  be  correspondingly  increased. 
But  this  increase  is  not  directly  according  to  a  decrease  in  size,  as 
noted  in  a  preceding  paragraph  where  it  was  found  that  the 
cement  doubled  as  the  stone  quartered  in  diameter. 


ERECTING  FOUNDATIONS  79 

CONCRETE  WITH  FINE  STONE  OR  GRAVEL. 

That  the  proportions  of  fine  and  coarse  material  suitable  for 
large  aggregate  will  not  work  with  finer  material  is  readily  seen  by 
reference  to  curve  B,  along  which  the  dotted  line  /  has  been  laid 
down  to  represent  a  mixture  of  16  2/3  per  cent,  cement,  33  1/3 
per  cent.  No.  20  sand,  and  50  per  cent,  of  No.  2  stone  or  gravel. 
This  means  a  1-2-3  mixture,  and  it  will  be  noted  that  its  curve 
(the  dotted  line  /)  does  not  coincide  very  closely  to  curve  B, 
hence  this  proportion  would  not  be  a  desirable  one  for  i/^-inch 
aggregate,  though  it  works  pretty  well  with  certain  larger 
material. 

Let  the  quantity  of  fine  material  be  reduced  to  equal  the 
cement — one  part — which  is  laid  down  on  curve  e,  and  together 
with  the  cement  forms  33  1/3  per  cent,  of  the  mixture,  leaving 
66  2/3  per  cent,  of  No.  2  stone  or  gravel.  This  mixture  corre- 
sponds to  1-1-4,  and  it  follows  the  B-curve  quite  closely.  It  is 
evident,  however,  that  the  concrete  could  be  slightly  improved  by 
replacing  some  of  the  No.  2  material  with  an  equal  quantity  of 
No.  4,  thereby  causing  curve  e  to  approach  B  more  closely  at 
the  70  per  cent,  intersection.  Again,  if  the  No.  20  sand  were 
replaced  by  No.  12,  and  the  quantity  increased  until  with  the 
cement  it  amounted  to  35  per  cent.,  curve  B  would  be  still  more 
closely  approached  at  the  No.  8  35  per  cent,  point,  the  intersec- 
tion at  e  being  carried  almost  directly  upon  curve  B. 

But  with  the  proportions  of  1-1-4,  as  laid  down  in  Fig.  29-a  by 
curve  e,  the  author  has  repeatedly  made  test  blocks  requiring 
a  crushing  load  of  over  2000  pounds  to  break  them  when  seven 
days  old,  and  the  absorption  of  these  blocks  averaged  less  than 
7  per  cent,  by  weight.  Thus  it  is  evident  that  the  millwright  may 
make  up  a  pretty  good  concrete  with  almost  any  form  of  material, 
provided  he  can  keep  the  percentages  in  the  curves  which  "run 
ashore"  in  the  100  per  cent,  ordinate  of  the  largest  material  used. 

LIME  IN  CEMENT  MORTAR. 

It  is  very  hard  to  make  cement  mortar  work  easily  under  the 
trowel,  unless  an  excess  of  cement  be  present  above  the  two  or 
three  parts  of  sand  to  one  volume  of  cement,  as  usually  mixed. 
In  such  cases,  it  is  usual  to  mix  a  quantity  of  lime  with  the  cement 
mortar.  It  has  been  found  that  10  per  cent,  of  the  cement  can  be 


80  MILLWR1GHTING 

replaced  by  hydrated  lime  with  good  results,  and  where  the  cement 
is  to  be  used  under  water,  a  much  larger  portion  of  lime,  even 
to  25  per  cent,  can  be  used  to  displace  an  equal  amount  of  cement 
without  decreasing  the  strength  of  the  mortar.  For  dry  work, 
however,  no  more  than  10  per  cent,  of  lime  should  be  used  and 
that  lime  should  be  the  hydrate.  Quicklime  paste  will  not  show 
as  good  results  as  the  hydrate.  Natural  cement  will  stand  even 
more  lime  than  will  portland. 

HYDRATED  LIME  AND  LIME  MORTAR. 

A  recent  addition  to  the  masons'  stock  in  trade  is  hydrated 
lime.  It  is  no  longer  necessary  to  purchase  lime  in  lumps  and  to 
go  through  the  tedious  process  of  "slaking"  the  lime,  then  letting 
it  lie  from  one  to  three  weeks  to  become  properly  "aged."  Instead 
of  this,  the  millwright  can  obtain  lime  in  bags,  the  same  as  cement 
comes,  and  all  ready  to  be  mixed  with  sand  and  water  and  at 
once  laid  in  the  wall.  This  kind  of  lime  may  be  mixed  up  in 
advance  if  desired,  but  it  does  no  good  (neither  does  it  do  any 
harm),  for  hydrated  lime  requires  no  aging  as  is  the  case  when 
lump  lime  is  slaked;  the  reason  for  which  is  that  lime  cannot 
slake  instantly,  and  that  some  portions  of  a  cask  require  much 
more  time  than  other  portions,  that  once  the  lime  is  wet,  the 
hydration  will  continue  until  it  is  complete,  provided  sufficient 
water  is  present,  hence  the  necessity  for  placing  the  wetted  quick- 
lime one  side  for  several  days — or  weeks — according  to  the  kind 
of  lime,  until  hydration  is  fully  completed.  The  process  of  hydra- 
tion has  been  fully  carried  out  in  hydrated  lime,  hence  it  is  ready 
for  immediate  use  as  soon  as  mixed  with  sand  and  water. 

SLAKING  LIME. 

Whenever  it  is  necessary  to  slake  lime  in  the  old-fashioned 
way,  the  millwright  should  see  that  sufficient  water  is  present 
during  the  operation.  Lime  will  increase  in  weight  from  25  to 
30  per  cent,  during  the  hydrating  process,  but  from  40  to  50  per 
cent,  of  water  is  necessary  to  perform  the  work  of  hydration. 
Although  only  about  one-half  the  quantity  of  water  supplied  to 
the  lime  is  absorbed,  the  remainder  is  dissipated  in  the  form  of 
steam,  and  the  presence  of  this  excess  of  water  is  very  necessary 
to  keep  down  the  heat  developed  during  the  slaking  or  hydrating 


ERECTING  FOUNDATIONS  81 

operation,  which  is  carried  off  by,  and  is  used  in  generating  the 
steam  which  escapes  during  the  operation. 

A  high  degree  of  heat  is  developed  during  the  union  of 
water  and  quicklime,  and  unless  the  heat  thus  developed  is  con- 
veyed away  from  the  lime  re-crystalization  takes  place  and  the 
value  of  the  lime  is  seriously  impaired.  The  common  name  for 
the  process  is  "burning,"  and  a  sufficient  quantity  of  water  should 
always  be  present  to  carry  off  in  the  form  of  steam  the  excess  of 
heat  generated  during  the  slaking  operation.  Thus  it  is  of  value 
to  provide  plenty  of  water  when  lime  is  to  be  slacked,  and  later 
to  place  the  slaked  lime  one  side,  or  bury  it  in  the  ground,  for 
many  days  before  using.  It  will  do  no  harm  for  slaked  lime  to 
remain  for  weeks,  or  even  for  months,  well  covered  in  the  ground, 
where  no  carbonic  oxide  can  get  at  it.  Lime  can  only  harden  by 
reabsorbing  carbonic  oxide  from  the  air  or  from  its  surroundings ; 
therefore,  keep  the  lime  from  the  air  and  it  will  keep  indefinitely. 


CHAPTER  VII. 

ERECTION  OF  BUILDINGS. 

When  buildings  are  to  be  erected  by  contract,  plans  and  speci- 
fications having  been  prepared,  the  millwright  frequently  has  to 
fill  the  position  of  inspector,  and  it  is  his  business  to  see  that  no 
poor  material  or  bad  workmanship  is  put  into  the  structure. 
When  the  labor  is  being  done  by  the  owner,  and  possibly  by  the 
millwright  in  charge,  he  must  be  ready  to  specify  what  shall 
not  be  done  and  what  shall  be  done  in  order  to  expedite  the  work. 
In  the  one  case,  the  millwright  need  only  see  that  the  specifications 
and  drawings  are  lived  up  to,  while  in  the  other  he  is  virtually  the 
constructing  engineer,  and  to  a  great  extent  the  cost  of  the  con- 
struction will  depend  upon  his  efforts. 

MASONRY  CONSTRUCTION. 

The  methods  of  masonry  construction  are  so  well  known  that 
the  millwright  will  have  little  trouble  to  keep  the  project  up  to  its 
proper  standard  and  at  the  same  time  turn  out  the  maximum 
amount  of  work.  The  providing  of  material  and  the  getting  it 
to  the  hand  of  the  worker  at  the  exact  instant  it  is  needed  are  a 
large  part  of  the  work  cut  out  for  the  supervisor  of  construction. 
But  the  greatest  part  of  the  work  is  to  see  that  no  time  is  lost, 
that  improved  methods  are  used  and  that  the  best  work  possible 
is  done. 

LAYING  BRICK. 

To  keep  the  bricklayers  at  all  times  keyed  up  to  their  highest 
degree  of  efficiency  will  tax  the  powers  of  the  millwright,  but 
he  can  do  it  by  giving  attention  to  a  few  things.  Let  the  spirit 
of  competition  be  awakened  among  the  men,  and  start  two  or 
more  gangs  at  the  same  time  on  similar  work  and  give  some 
inducement,  moral  or  otherwise,  for  them  to  enter  into  competition 
with  each  other. 

82 


ERECTION  OF  BUILDINGS  83 

See  that  the  head  man  on  each  line  has  charge  of  that  line, 
and  let  him  give  his  undivided  attention  to  keeping  the  line  drawn 
all  the  time.  Let  the  head  man  have  full  and  absolute  control 
over  the  men  under  him  on  his  line  and  give  no  instructions  to 
those  men  save  through  the  head  man.  See  that  mortar  is  used 
freely  and  is  kept  plentifully  supplied  and  in  the  best  possible 
condition.  Have  all  joints  made  by  sliding  the  bricks  endwise, 
and  see  that  the  head  man  permits  no  loss  of  time  in  pointing, 
while  a  few  men  could  be  hastening  matters  greatly  by  occasion- 
ally stepping  over  the  wall  and  helping  level  up  for  header  courses. 

CONCRETE  CONSTRUCTION. 

For  stone  construction,  tactics  much  the  same  are  in  order  to 
get  the  work  done  quickly  and  well,  and  in  concrete  construction 
there  is  the  opportunity  of  a  lifetime  to  save  time  in  getting  work 
out.  Just  how  to  do  it  will  depend  largely  upon  the  work  and 
surroundings  and  the  quality  of  the  man  in  charge. 

Once  the  molds  are  constructed  and  in  place,  it  is  especially 
desired  that  they  be  made  water-tight  before  the  concrete  is 
poured.  This  may  be  done  by  making  the  joints  in  the  forms  as 
tight  as  possible  and,  where  necessary,  by  closing  them  with  ordi- 
nary mortar,  though  plaster  of  paris,  puty,  sheathing  paper  tin 
and  cloth  are  used  for  that  purpose  as  occasion  requires. 

The  oiling  of  forms  should  also  be  carried  out  on  face  work, 
though  in  places  where  the  forms  can  be  left  in  place  until  the  con- 
crete is  thoroughly  dry,  oiling  is  not  necessary  if  the  forms  be 
thoroughly  wet  before  the  concrete  is  poured.  Almost  any  kind 
of  oil  may  be  used,  crude  petroleum  being  frequently  used,  also 
linseed  oil,  fish  oil,  soft  soap  and  other  greasy  substances. 

MAKING  AND  PLACING  FORMS. 

When  concrete  work  first  came  into  use,  the  forms  were  made 
on  the  spot  by  carpenters  or  "wood-butchers,"  as  could  be 
obtained.  At  the  present  somewhat  advanced  state  of  the  art  of 
concrete  construction,  most  of  the  forms  are  made  in  a  wood-shop, 
in  a  workmanlike  manner,  from  designs  prepared  by  competent 
engineers  and  draftsmen,  and  these  forms  will  not  fail  in  their 
allotted  work.  In  making  designs  for  forms,  the  weight  of  the 
concrete  is  taken,  including  the  reinforcement,  as  154  pounds  to 


84  MILLWRIGHTING 

the  cubic  foot.  There  is  also  assumed  a  live  load,  including  the 
weight  of  the  workmen,  their  material  and  tools,  the  weight  of 
unused  material,  etc.,  which  may  be  taken  at  75  pounds  a  square 
foot  when  making  forms  for  floors,  and  50  pounds  when  working 
beams  and  girder  forms. 

STRENGTH  OF  WOODEN  FORMS. 

The  allowable  compression  in  struts  to  support  forms  is 
between  600  and  1.200  pounds  to  the  square  inch,  according  to  the 
size  and  length  of  the  strut;  and  when  timber  beams  are  used 
for  supporting  forms,  including  the  material  in  the  form  itself, 
the  extreme  fiber  stress  may  be  taken  at  750  pounds.  In  most 
computations  for  forms,  the  deflection  of  the  material  is  to  be 
considered  rather  than  its  strength,  and  the  deflection  should  be 
figured  not  to  exceed  %  inch  for  beams  and  joist  work. 

When  the  compression  strain  approaches  700  pounds  to  the 
square  inch  in  soft  woods  across  the  grain,  either  brackets  must 
be  inserted  to  carry  the  load  or  hardwood  cleats  must  be  used. 
The  modulus  of  elasticity  of  soft  woods  usually  employed  in  form 
construction  may  be  taken  at  1,300,000  pounds  to  the  square  inch. 

TIME  TO  REMOVE  FORMS. 

As  a  guide  to  the  millwright  for  the  time  forms  should  be  left 
in  place  after  concrete  work  is  poured,  may  be  cited  the  following 
rules  in  use  by  The  Aberthaw  Construction  Company : 

Walls  in  mass  work :  one  to  three  days,  or  until  the  con- 
crete will  bear  pressure  of  the  thumb  without  indention. 

Thin  walls:  in  summer,  two  days;  in  cold  weather,  five 
days. 

Slabs  (floors)  up  to  6  feet  span:  in  summer,  six  days;  in 
cold  weather,  two  weeks. 

Beams  and  girders  and  long  spans :  in  summer,  ten  days 
or  two  weeks ;  in  cold  weather,  three  weeks  to  one  month.  If 
shores  are  left  without  disturbing  them,  the  time  of  removal 
of  the  sheeting  in  summer  may  be  reduced  to  one  week. 

Column  forms :  in  summer,  two  days ;  in  cold  weather, 
four  days,  provided  girders  are  shored  to  prevent  appreciable 
weight  from  reaching  columns. 

Conduits :  two  to  five  days,  provided  there  is  not  a  heavy 
fill  upon  them. 

Arches:  of  small  size,  one  week;  for  large  arches  with 
heavy  load,  one  month. 


ERECTION  OF  BUILDINGS  85 

All  these  times  are,  of  course  simply  approximate,  the 
exact  time  varying  with  the  temperature  arid  moisture  of  the 
air  and  the  character  of  the  construction.  Even  in  summer, 
during  a  damp  cloudy  period,  wall  forms  cannot  sometimes 
be  removed  inside  of  five  days,  with  other  members  in  pro- 
portion. Occasionally,  batches  of  concrete  will  set  abnormally 
slow,  either  because  of  slow-setting  cement  or  impurities  in 
the  sand,  and  the  foreman  and  the  inspector  must  watch  very 
carefully  to  see  that  the  forms  are  not  removed  too  soon. 
Trial  with  a  pick  may  assist  in  reaching  a  decision. 

Beams  and  arches  of  long  span  must  be  supported  for  a 
longer  time  than  short  spans  because  the  dead  load  is  propor- 
tionally large,  and  therefore  the  compression  in  the  concrete 
is  large  even  before  the  live  load  comes  upon  it. 

The  general  uncertainty  and  the  personal  element  which 
enters  into  this  item  emphasize  the  necessity  for  some  more 
definite  plan  of  securing  safety.  The  suggestion  has  been 
made  that  two  or  three  times  a  day  a  sample  of  concrete 
be  taken  from  the  mixer  and  allowed  to  set  on  the  ground, 
under  the  same  conditions  as  the  construction,  until  the  date 
when  the  forms  should  be  removed.  These  sample  specimens 
may  then  be  put  in  a  testing  machine  to  determine  whether 
the  actual  strength  of  the  concrete  is  sufficient  to  carry  the 
dead  and  construction  loads.  Even  this  plan  does  not  provide 
for  the  possibility  of  an  occasional  poor  batch  of  cement, 
so  that  watchfulness  and  good  judgment  must  also  be 
exercised. 

.  REINFORCED  CONCRETE. 

In  looking  after  the  erection  of  reinforced  concrete  work,  the 
millwright  may  have  to  design  small  bits  of  construction,  but  the 
majority  of  such  work  should  be  designed  by  competent  engi- 
neers who  have  specialized  in  that  branch  of  engineering.  It  is 
to  the  credit  of  the  millwright  should  he  study  that  form  of  con- 
structural  work,  and  it  may  be  taken  in  connection  with  regular 
structural  engineering. 

To  determine  the  "layout"  necessary  for.  a  piece  of  reinforced 
concrete,  several  things  must  be  determined.  First,  the  strains 
in  any  member.  Second,  the  amount  of  each  strain.  Third,  the 
direction  and  location  of  each  strain.  These  points  having  been 
determined,  it  is  easy  for  the  millwright  to  calculate  how  large 
a  steel  section  will  be  required  to  carry  each  strain  or  load,  and 
then  he  can  place  the  necessary  sections  of  steel  exactly  where  they 
are  required. 


86 


MILLWRIGHTING 


As  elsewhere  stated,  the  best  construction  calls  for  the  use  of 
just  steel  enough  (taken  with  the  proper  factor  of  safety)  to 
carry  the  tensile  strains  and  just  concrete  enough  to  carry  the 
compressive  strains. 

CALCULATING  A  MACHINERY  PIER  OF  REINFORCED  CONCRETE. 

This  book  cannot  be  devoted  to  reinforced  concrete  to  any 
extent,  but  to  give  the  millwright  an  idea  of  the  manner  in  which 
the  calculations  are  made  for  this  form  of  construction,  the  fol- 


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FIG.    30.— CALCULATING   A    REINFORCED    CONCRETE   FOOTING. 


ERECTION  OF  BUILDINGS  87 

lowing  illustration  and  calculations  are  given  for  ascertaining 
the  steel  and  concrete  necessary  for  a  pier  footing,  or  for  the  foot- 
ing of  a  machine  foundation,  according  to  the  Ransome  system, 
as  shown  in  a  booklet  issued  by  The  Ransome  Machinery 
Company. 

The  pier  shown  by  Fig.  30  is  to  carry  a  load  of  80  tons,  and 
the  safe  bearing  power  of  the  soil  is  2  tons  to  the  square  foot. 
This  means  that  there  must  be  40  square  feet  in  the  area  of  the 
footing,  and  its  width,  W ,  will  be  the  square  root  of  40,  or  6  feet, 
4  inches,  or  76  inches.  The  width  of  the  pier  is  16  inches, 
therefore  the  projection  of  the  footing,  P,  must  equal  one-half  of 
76  inches  —  16  inches  or  30  inches.  The  rule  followed  by  this 
concern  for  stress  in  the  reinforcing  of  footings  is  that  the  load 
multiplied  by  the  projection  of  the  footing  shall  not  be  greater 
than  three  times  the  depth  of  the  reinforcing  from  the  point 
where  the  load  is  applied  to  the  footing. 

The  above  is  evidently  based  upon  the  rule  by  the  same  com- 
pany for  wall  footings,  that  whenever  the  safe  compressive 
strength  of  the  concrete  equals  35  tons  to  the  square  foot  there 
shall  be  16  square  inches  in  the  area  above  the  bars  for  each  ton 
stress,  or  16  x  stress  =12  x  depth,  or  the  stress  equals  %  of  the 
depth.  The  stress  in  tons  is  %  distance  of  iron  in  inches  from  the 
top  of  pier. 

But  in  the  rule  for  pier  footings,  the  formula  has  been  modified 
to  fit  a  short  wall  instead  of  a  continuous  one,  with  the  footing 
projecting  equally  on  all  sides,  and  they  say  that  the  stress  shall 
not  be  greater  (in  tons)  than  one-eighth  of  the  depth  of  iron  in  the 
concrete  multiplied  by  the  width  of  the  column  where  it  joins  the 
footing,  plus  6.  If  this  value  for  the  stress  be  substituted  in  the 
rule  given  above,  it  is  found  that  the  depth  D  equals  the  square 
root  of  8  times  the  product  of  the  load  L  and  projection  P,  divided 
by  3  times  the  width  W,  plus  6. 

All  the  numerical  quantities  in  this  expression  are  known, 
and  bringing  them  together,  we  find  that : 

D  equals  the  square  root  of—  —17,  and  the  stress  will 

o  X  2i2i 

be  — X  17=47  tons.    This  equals  94,000  pounds,  and  as  a  Ran- 

8 
some  twisted  square  bar  or  rod  %  inch  on  a  side  is  tabulated  as 


88 


MILLWRIGHTING 


being  good  for  85,240  pounds  to  the  square  inch  to  its  ultimate 
strength,  one-fourth  this,  or  21,310  pounds,  is  its  safe  working 
stress.  The  cross-sectional  area  of  a  94-inch  r°d  *s  9/16  inch, 
and  the  rod  will  be  good  for  9/16  of  21,210=12,000  pounds. 
Then,  94,000-^-7,840=7.84  rods  required.  As  it  is  not  possible 
to  use  a  fraction  of  a  rod,  eight  rods  must  be  used,  and,  in  order 
to  make  the  disposal  of  the  rods  symmetrical,  also  to  place  one 
rod  in  the  center  of  the  pier  as  shown  by  Fig.  30,  it  will  be  neces- 
sary to  use  an  odd  number  of  rods  and  to  increase  the  number  to  9. 
Should  it  be  desired  to  use  %-inch  rods  instead  of  %-inch,  the 
number  required  is  found  to  be  17.45,  and  for  the  reasons  noted 
above,  this  number  is  increased  to  18  and  to  19.  A  table  of  Ran- 
some  bars  is  given  as  follows : 

TABLE  II.— RANSOME  BARS. 


Size  of  Bar. 

Weight  to 
the  Foot 

Elastic- 
Limit 

Ultimate 
Strength. 

1|  inch  square.  .  .  . 
1     inch  square.... 
|  inch  square  .  .  . 
f  inch  square  .  .  . 
f  inch  square  .  .  . 
\  inch  square.  .   . 
f  inch  square.  .   . 
\  inch  square.  .  . 

5.312 
3.400 
2.603 
1.913 
1.328 
.850 
.478 
.213 

55,450 
55,760 
56,150 
56,720 
57,890 
60,120 
61,800 
62,350 

83,150 

84,730 
84,730 
85,240 
85,820 
86,350 
86,600 
86,700 

The  shape  of  the  Ransome  bar  is  shown  by  Fig.  31,  and  the 
bar  is  found  to  resemble  about  as  closely  as  possible  the  square 
twisted  lightning  rods  so  commonly  in  use  a  few  years  ago.  It 
will  be  noted  that  the  smaller  the  bars  the  greater  their  elastic 
limit  and  their  ultimate  strength — a  convincing  argument  in  favor 


FIG.   31.— A  RANSOME  BAR. 


of  using  as  small  a  bar  as  possible  in  every  instance,  provided  it 
is  possible,  with  the  small  bars,  to  obtain  the  desired  strength  of 
metal  without  taking  up  too  much  room.  There  is  another  very 
strong  argument  in  favor  of  the  small  bar,  and  that  is :  with  the 
small  bar,  more  surface  is  exposed  to  the  cement,  therefore  more 


ERECTION  OF  BUILDINGS  89 

holding  power  to  transmit  the  strains  from  concrete  to  steel,  or 
contrariwise. 

The  above  matter  is  easily  determined.  In  a  bar  1  inch  square, 
there  are  4  square  inches  of  holding  surface  to  each  lineal  inch 
of  bar.  In  the  i/^-inch  bar,  there  are  just  2  inches  of  holding  sur- 
face to  the  lineal  inch,  and  as  the  strength  of  the  1-inch  bar  is 
four  times  the  strength  of  the  %-inch  bar  and  its  surface  is  only 
twice  as  great,  it  will  readily  be  seen  that  the  i/o-inch  bar  has  twice 
the  holding  power  according  to  the  strain  which  can  be  carried 
as  the  1-inch  bar. 

SOLVING  THE  FOOTING  PROBLEM  BY  ALGEBRA. 

For  the  millwright  who  desires  to  use  algebra  instead  of  plain 
arithmetic  in  solving  the  steel  reinforcing  problem  given  above, 
the  following  has  been  prepared.  It  is  exactly  the  same  solution 
as  is  given  above  but  it  is  expressed  in  letters  instead  of  words. 
The  millwright  should  by  all  means  study  algebra  enough  to 
enable  him  to  understand  it  when  it  is  met  with  in  books.  And 
once  this  knowledge  is  obtained,  the  millwright  will  use  algebra 
in  his  business.  Algebra  and  arithmetic  are  about  like  a  band 
saw  and  a  hand  saw.  You  can  do  the  same  work  well  with  either, 
but  one  is  ten  times  as  quick  and  twenty  times  as  easy  as  the  other. 
No  need  to  ask  the  millwright  which  is  which  in  that  problem, 
and  it  is  only  necessary  to  add  that  algebra  compares  with  the 
band  saw. 

CALCULATING  A  PIER-FOOTING  BY  ALGEBRA. 

Referring  to  Fig.  30: 
Width  of  pier,  W=16  inches. 
Width  of  footing,  W=76  inches. 

Total  load  carried,  L=80  tons,  including  weight  of  footing. 
Stress  in  tension  bars,  S=  ? 
Depth  of  tension  bars,  D=  ? 
Projection  of  footing  beyond  pier,  P=30. 
Formula  for  obtaining  stress  in  tension  bars  running  in  each 
direction  : 


(1) 

3XD 


90  MILLWRIGHTING 

In  the  above,  the  stress  and  the  depth  are  as  yet  unknown. 
In  order  that  concrete  may  not  be  compressed  beyond  its  safe 
working  strength,  it  has  been  assumed  that : 

(2)  4Xstress=-|-X  (W+6). 

Reducing  this  formula,  it  is  found  that 
(8)  s=DxCW+6) 

8 

Another  value  of  S  has  been  found  in  equation  (1),  and  sub- 
stituting that  value  in  equation  (3),  there  is  obtained: 
PL      D(W+6) 

3D  8 

Solving,  we  have: 


Or, 


.,.  „          8X80X30     1r7  .     . 

D=\      3X22     =17mches- 
But  from  formula    (3) 

00 

(7)  S=— Xl?=47  tons=94,000  pounds. 

8 

The  bars  should  be  spaced  equally  over  a  space  W — D=59, 
therefore  the  bars  should  be  about  5  feet  long.  As  the  total 
hight  of  the  footing  should  be  D+4  inches,  the  footing  will  be 
21  inches  thick  and  the  reinforcing  bars  will  be  placed  4  inches 
from  the  bottom. 

To  be  fair  with  algebra,  compare  the  above  with  the  arith- 
metic solution  of  the  problem  and  see  how  much  easier  it  is  to 
see  in  the  above  what  is  intended  to  be  done  in  the  several 
operations. 

OFFSETS  FOR  SOLID  MASONRY  FOOTINGS. 

The  proper  offset  for  solid  concrete  footings  (without  rein- 
forcing) may  be  found  by  the  following  table  by  Kidder,  which 
also  gives  the  necessary  data  for  calculating  footings  of  other 
material,  the  dimensions  being  given  as  multiples  of  the  thickness 
of  the  course  to  be  offset. 


ERECTION  OF  BUILDINGS 


91 


TABLE   III.— SAFE  LOAD   FOR   MASONRY   FOOTING   COURSES— KIDDER. 


Offset  for  a  pressure  to  the  square  foot  on 

Kind  of  Footing. 

R*  in 

pounds  to 
the  square 

the  bottom  of  the  course,  multiply  thick- 
ness of  course  by  the  proper  factor. 

inch 

0.5 

l 

2 

3 

5 

10 

Ton 

Ton 

Tons. 

Tons. 

Tons. 

Tons. 

Bluestone  flagging.  .  .  . 

2700 

3.6 

2.6 

1.8 

1.5 

1.2 

0.8 

Granite 

1800 

2  9 

2  1 

1.5 

1  2 

1  0 

0  7 

Limestone 

1500 

2  7 

1  9 

1  3 

1.1 

0  9 

0  6 

Sandstone 

1200 

2  6 

1  8 

1  3 

1.0 

0  8 

0  5 

Slate       

5400 

5  0 

3  6 

2  5 

2.2 

1.5 

1.2 

Best  hard  brick  

1200 

2.6 

1.8 

1.3 

1.0 

0.8 

0.5 

{1.  Portland 

2.  Sa™. 

150 

0.8 

0.6 

0.4 

3.  Pebbles 

{l.Rosendale 

2.  Sa™. 

80 

0.6 

0.4 

0.3 

3.  Pebbles.. 

*Modulus  of  rupture,  values  given  by  Prof.  Baker  in  "  Treatise  on  Masonry  Construction." 

INSPECTION  DURING  ERECTION. 

When  buildings  or  other  concrete  or  reinforced  concrete 
work  is  being  erected,  if  the  millwright  is  inspecting  the  work 
or  is  having  it  done  under  his  direction,  he  must  make  sure  from 
actual  knowledge  of  the  matter  that  the  proportions  of  cement 
and  sand  and  of  gravel  are  as  called  for  by  the  specifications. 
He  must  know  that  the  concrete  is  poured  or  rammed  so  that 
water  stands  on  the  surface.  He  must  know  that  the  required 
reinforcing  is  actually  put  in  place  as  required  by  the  drawings. 

It  must  be  known  that  the  concrete  is  packed  fully  and  com- 
pactly around  each  piece  of  steel  in  the  reinforcement,  and  that 
there  are  no  voids  caused  by  leakage  of  cement  from  the  forms. 
The  writer  has  more  than  once  seen  scurrying  around  and  amus- 
ing attempts  made  to  stop  a  leak  in  a  form  for  fear  that  the 
cement  would  run  out  and  leave  the  beam  weak  and  unable  to 
carry  its  load.  There  is  no  danger  of  such  a  happening  when 
there  is  a  leak  in  a  form.  The  danger  is  that  where  the  cement 
runs  out  there  will  be  a  void  in  the  construction,  and  what  weak- 
ening takes  place  will  be  from  a  hole  not  from  the  cement  run- 
ning away  from  the  aggregates. 

HOLDING  THE  CONTRACTOR  TO  SPECIFICATIONS. 
There  are  three  ways  of  doing  inspector  work,  but  only  one 
of  them  is  desirable.     The  first  way  is  to  hold  the  contractor 


92  MILLWRIGHTING 

rigidly  to  the  specifications,  to  make  him  toe  the  mark  whether 
there  is  a  reason  for  it  or  not,  and,  as  one  contractor  said  of  his 
inspector,  "The  cuss  lays  awake  nights  to  think  up  things  he  can 
kick  about."  It  is  needless  to  add  that  this  inspector  is  not 
beloved  by  the  contractor,  and  that  in  case  of  a  blunder  by  the 
inspector — and  inspectors  fall  down  at  times  the  same  as  all 
other  people — the  contractor  will  not  do  a  thing  to  help  the 
inspector  out  of  his  trouble. 

There  are  many  things  which  can  be  done  a  little  different 
than  called  for  by  the  specifications  and  still  be  as  good,  perhaps 
a  little  better,  and  not  cost  the  contractor  half  as  much.  This 
brings  us  to  the  second  method  of  inspecting,  the  one  which  alone 
is  of  value,  and  which  should  be  followed  by  every  millwright. 
It  costs  nothing,  obtains  big  results,  and  makes  things  pleasant 
all  around. 

THE  GIVE  AND  TAKE  METHOD  OF  INSPECTING. 

This  is  the  best  method  of  inspecting.  It  makes  the  contractor 
into  a  friend  who  will  do  anything  to  help  the  inspector,  and  who 
will  not  do  one  thing  when  the  inspector  is  present  and  another 
thing  when  that  official's  back  is  turned.  Let  the  contractor  be 
assured  that  the  inspector  desires  to  help  along  the  work  to  the 
utmost,  while  strictly  maintaining  the  required  character  of  the 
work,  and  things  never  drag  on  the  job.  The  concrete  is  always 
just  right,  the  steel  comes  into  place  almost  of  itself,  the  forms  go 
in  place  and  come  away  as  if  by  magic,  and  the  work  turned 
out  is  strong  and  perfect  in  requirements  and  in  appearances, 
while  the  contractor  is  making  money  hand  over  hand. 

INSPECTING  FOR  GRAFT. 

The  third  method  of  inspecting  is  where  the  contractor  can 
get  nothing  or  do  nothing  to  suit  unless  he  keeps  the  hand  of  the 
inspector  well  covered — yes,  well  filled — all  the  time.  The  "graft" 
inspector  is  heartily  despised  by  the  contractor;  and  he  is  fired 
by  the  owner — as  soon  as  discovered.  There  is  nothing  too  bad 
for  the  graft  inspector  to  do  to  the  contractor  in  order  to  get  a 
little  more  boodle  out  of  the  job.  And  there  is  nothing  too  bad 
for  that  sort  of  an  inspector  to  receive  from  his  employer.  Some 
contractors,  those  who  do  not  intend  to  do  work  any  better  than 


ERECTION  OF  BUILDINGS  93 

they  are  forced  to  do,  will  welcome  the  advent  of  the  graft 
inspector,  while  at  the  same  time  they  despise  him  and  will  "throw 
him  down"  the  moment  they  can  make  nothing  more  by  his 
rascality. 

There  are  other  contractors  who  will  report  a  graft  inspector 
so  quick  that  he  never  knows  in  what  manner  he  was  discharged 
— so  quickly  was  he  ousted  from  his  position.  The  millwright, 
in  what  inspecting  he  is  called  upon  to  do,  will  let  the  first  and 
last  methods  of  inspecting  severely  alone  and  will  stick  like  a  burr 
to  the  middle  course — a  pretty  good  way  to  do  in  other  things 
beside  reinforced  concrete  inspecting.  He  will  "give  and  take" 
and  show  good  results. 

WOODEN  FACTORY  CONSTRUCTION. 

A  great  change  has  taken  place  in  mill  construction  during 
the  past  few  years,  even  in  wooden  buildings  which  are  the  excep- 
tion rather  than  the  rule.  The  mortise,  tenon  and  pin  are  hardly 
ever  found  in  modern  mill  construction,  and  where  days  and 
weeks  were  spent  in  framing  harness-work  for  shafting,  there  is 
nowadays,  no  framing  to  be  found.  In  mills  built  according  to 
slow-burning  construction  rules,  the  lighter  timbers  have  entirely 
disappeared.  Floor  joist  and  bridging  have  been  replaced  by 
10xl4-inch  solid  timbers  and  3  to  5-inch  floor  plank.  The  roof 
is  as  heavy  as  a  floor  and  is  constructed  in  the  same  manner. 
There  is  no  sheathing,  and  consequently  no  covered-in  space  to 
conceal  rats'  nests  or  to  contain  fires  which  could  not  be  got  at 
until  after  the  roof  had  burned  off. 

FRAME  STRUCTURES. 

Mill  buildings  constructed  of  wood  are  so  scarce  that  it  hardly 
pays  to  spend  much  time  in  discussing  them,  save  that,  as  above 
noted,  they  are  built  according  to  slow-burning  construction 
rules,  or  else  they  are  mere  sheds,  thrown  up  "balloon  frame" 
fashion  for  temporary  use  or  to  be  later  replaced  or  enclosed 
with  brick  work. 

OLD-TIME  FRAME  CONSTRUCTION. 

Old-time  frame  construction  is  pretty  well  illustrated  by  Fig. 
32,  and  the  excessive  amount  of  handwork  necessary  for  the  mor- 


94 


MILLWRIGHT1NG 


tising,  tenoning,  brace-making  and  gain-cutting  may  well  be 
imagined.  In  the  engraving,  the  heavy  sill  is  shown  at  A,  a  post 
at  B,  and  a  girt  at  C.  These  timbers  were  made  anywhere  from 


FIG.  32.— SOME  OLD-TIME  FRAMING. 

10x10  inches  up  to  20x24  inches,  according  to  the  size  of  the 
building  and  its  hight.  The  wall  studs  E,  E,  were  framed  in  at 
both  top  and  bottom,  and  the  floor  joists  F,  F,  and  G,  G,  G, 
were  also  let  into  the  timbers  upon  which  they  had  a  bearing. 


ERECTION  OF  BUILDINGS  95 

The  cut  on  A,  at  c,  shows  how  the  floor  joist  F  was  framed. 
The  notch  or  gain,  cut  in  the  side  of  A,  permits  the  end  of  F  to 
enter,  and  the  shoulder  d,  left  on  F ,  is  made  just  right  to  reach 
the  foundation  of  the  building. 

The  upper  floor  joists  were  disposed  of  in  a  slightly  different 
manner,  made  necessary  by  the  fact  that  there  was  no  foundation 
for  the  floor  joists  to  rest  upon.  Accordingly,  the  upper  portion 
of  the  joist  G  was  allowed  to  project  over  the  top  of  girt  C,  and 
the  lower  edge  of  joist  G  was  carried  by  a  gain  cut  in  girt  C,  as 
shown  at  i.  By  this  arrangement,  the  joist  is  prevented  from 
splitting  between  i  and  /. 

The  post  B  is  mortised  into  sill  A,  as  shown  at  b,  the  sill 
being  broken  away  to  reveal  the  tenon  b  which  is  usually  made 
very  short  for  a  post.  The  tenons  on  the  upper  end  of  A  are  long 
enough  to  reach  nearly  half  way  through  girt  C.  Pins  are  used 
to  fasten  all  parts  of  the  frame  except  those  tenons  which  go 
into  the  sill,  which  does  not  receive  any  pins. 

SIZING  TIMBER. 

Another  thing  which  the  old-time  millwright  had  to  contend 
with  in  framing  a  mill  was  the  unequal  sizes  of  the  timbers  fur- 
nished. A  12xl2-inch  timber  would  be  anywhere  between  those 
dimensions  and  12%xll%  inches,  and  when  a  timber  was  the 
least  amount  larger  than  dimensions,  allowance  had  to  be  made  for 
the  extra  material  or  the  frame  would  never  go  together.  The 
mills  of  that  time  did  not  have  timber  planers.  Any  lumber  larger 
than  %-inch  boards,  or  possibly  2-inch  plank,  which  had  been 
planed,  was  a  curiosity  to  the  average  woodworker,  and  the  extra 
material  on  two  sides  of  nearly  every  timber  had  to  be  cut  away 
where  the  end  of  another  timber  came. 

Sizing  is  shown  at  e,  e,  also  at  h  and  at  k,  and  a  cut  through 
the  excess  of  material  is  also  shown  at  a,  where  the  sill  is  cut 
down  to  the  exact  dimension  size  in  order  that  the  studs  may  go 
into  place  without  striking  top  and  bottom  before  the  girts  are 
in  place.  Many  a  time  all  hands  have  been  held  up  with  a  big 
timber  held  aloft  on  pike-poles,  while  a  workman  skittled  up  a 
ladder  and  held  on  by  his  eyelids  while  he  hurriedly  cut  away  the 
shoulder  of  a  stud  in  order  to  make  up  for  a  forgotten  bit  of 
sizing  underneath  one  of  the  girts. 


96  MILLWRIGHTING 

Bracing  was  another  strong  point  in  the  old-time  method  of 
framing.  A  set  of  braces  is  shown  at  /,  in,  n  and  o,  each  brace 
being  mortised  and  pinned  at  each  end.  It  used  to  be  thought 
that  a  large  amount  of  bracing  was  necessary  to  make  a  frame 
stand  up  until  the  covering  could  be  put  upon  it,  hence  the  many 
dozens  of  braces  to  be  found  in  a  single  frame  building  of  the 
olden  style. 

Even  the  upper  studding  H,  H  was  mortised  in,  and  these 
studs  had  to  be  sized  for,  as  shown  at  p,  on  girt  C,  and  even  the 
beams  and  girders  had  to  be  sized  into  the  posts  sometimes.  A 
bit  of  sizing  is  shown  at  k,  the  beam  D  being  cut  into  post  B, 
as  shown.  But  this  time  the  work  is  not  for  the  purpose  of 
removing  an  excess  of  wood.  The  cutting  at  k  is  for  the  purpose 
of  giving  a  larger  bearing  to  D  than  would  be  afforded  by  the 
edge  of  the  tenon.  Therefore  a  half  inch  or  so  was  cut  out  of 
the  post  and  the  beam  allowed  that  much  more  bearing  surface. 
With  a  12-inch  post  and  a  3-inch  tenon,  there  would  be  4% 
square  inches  of  bearing  surface,  besides  the  16  to  18  inches  of 
area  on  the  edge  of  the  tenon. 

BALLOON  FRAMING. 

When  the  heavy  frame  went  out  of  fashion — chiefly  by  the 
higher  cost  of  lumber  and  labor — a  reaction  in  the  opposite  direc- 
tion set  in,  one  extreme  following  the  other,  as  usually  is  the 
case,  and  the  most  flimsy  framing  arrangement  it  was  possible  to 
devise  came  into  use  for  houses,  barns,  and  even  for  mills 
where  heavy  machinery  must  be  operated.  The  standard  method 
of  balloon  framing  is  shown  by  Fig.  33,  and  the  writer  has  seen 
mills  built  in  this  manner,  of  2x8-inch  material,  with  occasional 
reinforcement  of  2xl2-inch  stuff,  and  3  and  4-inch  shafting  hung 
directly  to  timbers  carried  by  the  light  framing  shown  by  the 
engraving — something  not  desirable  or  safe. 

In  the  pure  balloon  frame  the  sill  is  composed  of  two  pieces, 
usually  a  2x8-inch  and  a  2x6-inch,  spiked  together  as  shown  by 
A  and  B.  The  2x4-inch  or  2x6-inch  studs  are  cut  to  length,  as 
shown  by  C,  C,  C,  and  plain  at  each  end.  The  studs  are  nailed 
and  spiked  in  position,  being  toe-nailed  to  A,  and  spiked  through 
B.  The  floor  joists  are  cut  so  as  to  have  a  full  bearing  at  a  and 
b,  thus  removing  all  danger  of  split  floor  joists.  In  case  the 


ERECTION  OF  BUILDINGS 


97 


building  is  to  be  set  on  posts,  the  sill-plank  A  is  doubled  up,  the 
plank  B  being  made  as  wide  as  the  floor  joists,  which  then  will 
have  a  full  bearing  on  sill  A. 


FIG.   33.— BALLOON   FRAMING. 


The  second  story  floor  joists  are  put  in  place  as  shown  at  E, 
E,  a  ledger,  c,  being  let  into  the  line  of  studding  about  %  inch 
and  the  ledger  nailed  fast.  The  joists  E,  E  are  notched  on  to  the 
ledger  about  %  to  %  inch  as  shown,  and  then  they  are  spiked 


98  MILLWRIGHTING 

fast  to  the  studs,  which  holds  them  securely.  These  joists  are 
bridged  as  shown  at  e,  and  the  lower  floor  joists  are  also  bridged 
unless  a  timber  is  run  through  under  the  center  of  the  span. 
The  strapping  d,  d  is  next  put  in  position,  and  the  upper  floor 
may  be  put  in  at  will. 

A  2-inch  plate  is  spiked  on  top  of  the  studs,  the  rafters  G 
are  notched  and  nailed  upon  the  plate,  and  the  beams  above  the 
second  story  are  placed  on  the  plates  and  nailed  securely  thereto, 
besides  being  spiked  to  the  rafters,  a  joist  being  placed  close 
beside  each  of  the  rafters  for  this  purpose.  Sometimes  the 
upper  joists  are  notched  down  over  the  plate  %  inch  or  so,  and 
besides  holding  a  good  bit,  that  method  forms  a  very  good  means 
of  bringing  the  joists  into  position  on  the  plate.  Strapping,  /,  /, 
and  bridging  as  well,  are  applied  to  the  upper  joists  as  necessary, 
short  pieces  of  board,  i,  are  nailed  to  each  rafter  and  stud  to 
carry  the  coving  or  cornice,  the  wide  facier  of  which  is  indicated 
by  &. 

In  constructing  a  frame  by  this  method,  no  attention  whatever 
is  paid  to  the  location  of  either  windows  or  doors,  but  after  the 
studding  is  all  in  place  holes  are  cut  where  needed  for  the  various 
openings.  In  the  single  window  opening  shown  by  Fig.  33,  a 
single  stud  is  cut  out,  though  it  frequently  happens  that  two  or 
more  must  be  removed.  In  this  case  the  header  n  and  lintel 
/  are  cut  in,  then  the  short  studs  m,  m  are  put  in  position  to  hold 
up  the  lintel.  Short  studs  o,  o  are  then  cut  in  between  header 
and  lintel  placed  the  required  distance  apart  to  receive  the  window 
frame ;  then  the  short  studs  0,  o  are  doubled  up  to  receive  the 
weather-boarding  and  the  window  frame.  It  always  pays  to 
double  up  the  window  studs,  also  the  lintels  unless  plenty  of  studs 
are  placed  underneath  the  lintels. 

SHAFTING  HUNG  TO  BALLOON  FRAME. 

Whenever  the  writer  has  been  forced  to  put  shafting  of  any 
weight  into  a  balloon  frame  building,  it  has  been  his  custom  to 
put  in  a  heavy  ledger,  as  shown  at  A,  Fig.  34,  and  then  put  some 
bolts  b,  b,  through  ledger  and  studs,  instead  of  nailing  the  ledger 
in  the  usual  manner.  With  a  ledger  4x8  inches  let  into  the  studs 
1  inch  at  a,  and  bolted  securely  to  them  at  b,  b,  there  will  be  no 
trouble  in  sustaining  the  timbers  B,  B,  the  inner  ends  of  which 


ERECTION  OF  BUILDINGS 


99 


may  be  carried  on  posts  placed  for  that  purpose,  as  shown  by 
C,  C,  the  posts  being  in  turn  carried  by  a  stringer,  D,  which  also 
answers  to  carry  one  end  of  the  floor  joists  E,  E. 

The  timbers  B,  B,  instead  of  being  mortised  into  posts  C  as 
would  be  done  by  the  good  old-fashioned  way,  are  bolted  to 


FIG.  34.— SHAFTING  HUNG  TO  BALLOON  FRAME. 

them  by  a  single  %-inch  bolt  each,  well  washered,  and  then  a 
piece  of  2x8-inch  stuff  is  placed  against  the  post  and  spiked,  as 
shown  at  d  and  d.  This  gives  16  inches  of  bearing  surface  and 
the  timbers  B,  B  never  think  of  getting  loose  and  shaft  c  may  be 
placed  anywhere  desired. 

SLOW-BURNING  MILL  CONSTRUCTION. 

It  does  not  pay  to  bother  with  balloon  framing  or  mortise 
and  tenon  frames  when  the  type  known  as  slow-burning  mill  con- 
struction can  be  used.  This  form  of  construction  costs  a  little 
more  than  balloon  framing  but  not  as  much  as  the  mortise  and 
tenon  method  and  its  use  should  be  encouraged  whenever  the 
owners  can  not  be  made  to  use  reinforced  concrete  or  steel  con- 


100 


MILLWRIGHTING 


struction.  As  shown  by  Fig.  35,  the  construction  is  very  simple. 
Rows  of  posts,  A,  A}  A}  are  located  as  necessary  in  accordance 
with  the  load  to  be  carried,  and  beams  B,  B,  B  are  placed  on  top 
of  the  posts  as  shown ;  bolsters  D,  D,  D  are  placed  between  posts 
and  beams,  and  bolts  placed  through  each,  making  the  beams  con- 


FIG.    35.— SLOW-BURNING    CONSTRUCTION. 

tinuous.    The  beams  over  the  next  bent,  F,  are  fastened  as  above 
to  B,  etc.,  the  bolts  being  shown  at  a,  a,  a. 

If  the  load  is  to  be  very  heavy,  bearing  plates  c,  c,  c  are  placed 
as  shown  and  serve  not  only  to  protect  the  beams  B  and  F  from 
end-wood  of  the  posts,  but  also  as  bearings  for  the  planks  d  when 
the  latter  are  cut  in  between  the  posts.  Posts  C,  C,  C,  in  the  next 
story,  are  placed  as  shown,  and  in  this  manner  continued  to  the 


ERECTION  OF  BUILDINGS  101 

roof.  If  there  are  but  two  stories,  the  arrangement  is  as  shown 
by  the  engraving,  but  any  number  of  stories  up  to  four  may  be 
safely  framed  in  this  manner.  A  block  E  is  beveled  to  fit  the 
rafters  and  is  fastened  to  them  by  the  bolts  b,  b,  thus  uniting 
rafters  G  and  H  as  firmly  as  is  necessary.  When  necessary,  a 
truss  roof  may  be  used,  leaving  a  clear  upper  story. 

The  flooring  and  the  roofing  is  simply  thick  planking,  from  3 
to  5-inch,  according  to  the  distance  between  beams  B,  B,  B,  and 
the  load  to  be  carried  on  the  several  floors.  Sometimes  floors 
are  made  by  setting  2x4-inch  stuff  edgewise  and  spiking  them 
together  every  18  inches  with  20  penny  wire  nails. 

With  this  form  of  construction,  machines  may  be  located  any- 
where on  the  floor  of  the  factory,  and  unless  the  machines  are 
quite  heavy  no  reinforcing  of  the  floor  will  be  necessary.  The 
distance  between  beams  B,  B}  B  is  usually  about  6  feet,  and 
shafting  may  be  suspended  from  any  post  or  beam,  or  it  may  be 
placed  upon  the  floor  of  the  factory  at  will.  In  Fig.  35,  shafts 
are  shown  unsupported  at  No.  1,  attached  to  the  posts;  at  No.  2, 
and  No.  3  hung  underneath  and  placed  on  top  of  the  floor 
beams ;  at  No.  4  the  shaft  is  hung  to  an  upper  row  of  posts,  while 
shaft  No.  5  is  placed  on  the  floor  and  No.  6  is  hung  directly  from 
the  rafters. 

FRAMING  ON  THE  JOB  AND  AT  THE  MILL. 

The  old-time  method  of  framing  was  to  have  the  lumber 
dumped  on  the  ground  at  the  mill,  then  it  was  sorted,  piled,  and 
marked  out  by  the  "striker,"  after  which  each  piece  was  squared 
up,  mortised,  tenoned,  relished,  gained,  boxed,  or  otherwise  cut, 
as  required  by  the  form  of  construction  to  be  followed.  This 
method  of  doing  work  was  good  for  local  labor,  but  it  was  not  an 
economical  method  of  doing  work.  The  modern  way  of  procedure 
is  to  send  the  drawings  to  the  mill  where  the  bill  of  material  is 
to  be  gotten  out.  Send  a  man  with  the  bill — an  inspector,  if  you 
please,  or  the  millwright  or  a  good  framer — and  let  that  man  see 
that  the  material  is  properly  gotten  out  from  lumber  fitted  for  the 
several  purposes. 

In  a  mill  properly  arranged  for  framing,  the  cost  of  that  part 
of  the  work  will  be  reduced  from  %  to  *4  that  of  hand  framing, 
and  the  cost  of  lumber  will  also  be  considerably  reduced  for  the 


102  MILLWRIGHTING 

reason  that  at  the  mill  pieces  can  be  worked  to  better  advantage 
than  they  can  be  told  off  to  fill  a  schedule  of  lumber. 

ECONOMY  OF  MATERIAL — LUMBER — INSPECTION. 

The  inspection  of  lumber  for  market  purposes  calls  for  a  rigid 
adherence  to  certain  rules.  For  instance :  on  a  stick  of  certain 
size,  there  shall  not  be  more  than  a  certain  amount  of  wayne 
on  a  certain  number  of  corners.  There  also  shall  be  no  more 
than  certain  numbers  and  lengths  of  wind-shakes,  season-checks, 
and  similar  defects.  The  limit  exceeded,  the  inspector  has  no 
choice  whatever  except  to  condemn  the  piece  of  timber  thus  defec- 
tive and  reduce  it  to  a  grade  in  which  it  will,  according  to  the 
rules,  pass  muster. 

But  in  framing  at  the  mill,  the  fair-minded  inspector  can  in 
many  ways  favor  the  material,  so  that  what  would  have  to  be 
condemned  in  the  pile  will  pass  in  the  frame.  For  instance  in 
the  rule  against  wayne :  a  2x8-inch  rafter  would  have  to  be  con- 
demned if  it  showed  more  than  a  certain  width  of  bark  on  one 
or  more  corners,  whereas  in  the  building  nearly  the  entire  length 
of  the  rafter,  from  the  ridge  down  to  within  2  feet  of  the  plate, 
could  be  all  bark  edge  without  doing  the  least  damage  to  the 
strength  of  the  rafter,  for  those  members  of  the  building  economy 
do  not  need  to  be  as  wide  (deep)  at  the  top  as  at  the  bottom.  In 
fact,  rafters  are  frequently  sawed  2  inches  narrower  at  the  top 
than  at  the  bottom.  The  inspector,  bearing  that  fact  in  mind,  can 
pass  lumber  into  good  rafters  which  he  would  have  to  condemn 
in  the  pile. 

In  another  instance:  the  rule  against  large  knots  would  con- 
demn many  pieces  for  rafters  which  could  be  used  for  gable 
rafters  or  where  they  would  be  otherwise  supported.  The  same 
is  true  of  floor  joists  and  all  floor  timber.  It  does  no  harm 
whatever  for  a  floor  timber  to  be  narrower  at  the  ends,  provided 
the  middle  of  the  timber  is  full  depth.  A  lot  of  wayne  at  either 
or  both  ends  could  be  passed  into  the  frame  without  in  the  least 
affecting  the  strength  of  the  structure.  In  many  ways,  of  which 
the  above  are  merely  samples,  the  inspector- framer  can  save  money 
for  his  company  by  framing  at  the  mill.  The  writer  has,  in  more 
than  one  instance,  purchased  a  frame  at  a  reduction  of  several 
dollars  on  a  thousand,  and  economized  to  the  extent  of  a  thousand 


ERECTION  OF  BUILDINGS  103 

or  two  feet  of  lumber,  by  taking  the  lumber  mill-run  and  using 
it  as  common-sense  dictated,  placing  merchantable  pieces  where 
strength  was  required  and  working  the  culls  into  the  frame  where 
they  could  be  used  without  injury — and  there  are  lots  of  such 
places  to  be  found  by  those  looking  for  them. 

In  framing  at  the  mill,  it  is  meant  that  not  only  is  the  actual 
work  of  framing  done  at  the  mill,  but  the  cutting  is  also  done 
in  the  mill,  by  power,  the  cutting-off  being  done  with  power  saws, 
the  cutting  of  shoulders  being  done  in  that  manner,  and  the  bor- 
ing and  boxing  (or  dapping)  all  being  done  by  power  machines. 

LAYING  OUT  FRAMING. 

By  the  old  methods,  mortises  and  tenons  were  laboriously 
laid  out  with  steel  square  and  pencil,  the  distances  first  having 
been  measured  with  12-foot  pole,  rule  or  square.  Fig.  36  shows 
the  time-honored  way  it  is  done :  the  mortise  having  been  located 
endwise  by  a  mark  made  at  b,  the  square  is  put  in  position  as 
shown,  the  mark  b  drawn  clear  across  the  timber ;  then  the  square 


FIG.  36.— LAYING-OUT  WITH  THE  STEEL  SQUARE. 

is  slid  along  until  the  length  of  the  mortise  is  shown  on  the  blade 
of  the  square — 10  inches — as  shown.  Then  the  pencil  is  drawn 
across  the  timber  for  the  other  end  of  the  mortise  a,  but  the  pencil 
must  be  drawn  along  the  inside  edge  of  the  tongue  of  the  square. 
If  it  is  desired  to  mark  along  the  outside  of  the  tongue,  then  Sy2 
inches  must  be  taken  on  the  blade  instead  of  10  inches. 


104 


MILLWRIGHTING 


To  mark  the  sides  of  the  mortise,  a  mark  c  is  made  the  .required 
distance  from  the  face  of  the  timber  c;  then  the  square  is  placed 
as  shown ;  if  a  2-inch  mortise  is  to  be  made,  with  the  corner 
of  the  blade  on  the  mark  c.  Then  sight  the  blade  true  with 
face  of  timber  e,  and  mark  both  sides  of  the  blade,  thus  mark- 
ing1 the  sides  of  the  mortise.  When  greater  accuracy  is 
required,  reverse  the  square,  placing  the  inside  edge  of  the  blade 
on  mark  c  well  toward  the  end  of  the  blade  farthest  from  the 
tongue.  Then  bring  the  mark  2  on  the  tongue  even  with  face  of 
timber  e,  and  both  sides  of  the  mortise  may  be  marked  as  before. 

THE  LAYING-OUT  GAGE. 

The  modern  method  of  marking  for  mortises,  tenons,  and 
more  especially  for  daps  and  gains,  is  by  the  use  of  the  laying-out 
gage  shown  by  Fig.  37.  This  tool  is  usually  made  by  the  mill- 
wright, though  it  may  be  found  on  sale  in  some  of  the  larger 
hardware  stores.  A  couple  of  pieces  of  %,  1  or  1^-inch  stuff 


FIG.    37.—  A   LAYING-OUT  GAGE. 


may  be  used,  according  as  the  tool  is  designed  for  light  or  heavy 
work.  The  pieces  are  nailed  or  screwed  together  as  shown  by 
Fig.  37,  and  laid  off  and  cut  to  measure  according  to  that  picture. 
The  upper  pieces  are  made  to  the  several  lengths  likely  to  be  used 
by  the  mortises  or  daps  in  the  sizes  of  timber  under  operation. 


ERECTION  OF  BUILDINGS  105 

The  lower  side  of  the  gage  is  marked  to  the  widths  shown  by 
the  several  figures,  the  first  being  the  distance  from  the  face  of 
a  timber  to  a  mortise  with  a  2-inch  shoulder,  the  second  step 
making  a  4-inch  mark,  etc.,  as  many  jogs  being  made  as  the  mill- 
wright judges  he  will  have  use  for.  The  angle  at  which  the  pieces 
are  nailed  together  should  be  slightly  greater  than  a  right  angle, 
for  should  some  of  the  timber  be  sawed  as  far  from  square  as 
usual,  a  strictly  square  gage  would  not  go  on  the  corner  of  the 
timber.  About  95  degrees  is  all  that  is  necessary.  Any  timber 
which  is  so  badly  out  of  square  that  a  95-degree  gage  will  not 
go  on  had  better  be  trued  up  a  little  before  the  timber  is  laid  out 
for  framing. 

USING  THE  LAYING-OUT  GAGE. 

A  method  of  using  the  laying-out  gage  is  shown  by  Fig.  38. 
Supposing  that  a  2xlO-inch  dap  is  required,  all  that  is  necessary 
is  to  slide  the  10-inch  portion  of  the  gage  up  to  marked  point  a, 
then  draw  the  pencil  along  both  sides  of  the  10-inch  portion  of  the 
gage,  marking  both  lines  a  and  b  without  shifting  the  tool.  It 
happens  that  the  gage  is  also  in  position  so  that  line  c  can  be 


FIG.  38.— MARKING  "DAPS"  WITH  THE  LAYING-OUT  GAGE. 

marked  along  the  edge  of  the  2-inch  portion,  but  if  the  dap  is 
to  be  some  other  depth  than  2  inches,  then  it  is  only  necessary  to 
slide  the  gage  along  until  the  required  width  of  marking  strip 
comes  over  the  end  lines  of  the  dap — or  "box"  as  some  millwrights 
prefer  to  call  it.  The  gage  must  then  be  reversed  and  the  lines 
struck  down  to  line  c,  from  lines  a  and  b,  respectively. 


106  MILLWRIGHTING 

This  instrument  is  particularly  desirable  in  working  wayney 
timber  upon  which  it  is  hard  to  make  a  square  stay  in  position. 
When  making  mortises  and  tenons,  both  the  mortise  and  the  tenon 
as  well  are  struck  with  the  same  sections  of  the  gage,  and  the 
holes  in  the  upper  portion  of  the  gage  are  for  the  purpose  of  mark- 
ing for  the  pin-hole  to  be  made  in  each  mortise  or  tenon — the 
"draw-bore"  as  it  is  sometimes  called.  The  required  draft  has  to 
be  allowed  on  the  tenon  as  the  holes  mark  all  alike,  both  mortise 
and  tenon,  and  it  is  not  possible  to  tip  up  the  gage  when  marking 
the  draw-bore  on  the  tenon  as  is  the  usual  practise  when  the  square 


FIG.   39.— MARKING   "DRAW-BORES"  WITH  A   STEEL   SQUARE. 

is  used  for  that  purpose.  Fig.  39  shows  the  method,  the  square 
being  applied  as  shown,  the  center  of  the  stick  or  the  required 
location  of  the  hole  being  taken  at  a.  The  tipping  of  the  square 
causes  the  distance  from  shoulder  to  hole  to  be  foreshortened,  the 
width  of  square  tongue  or  blade  forming  the  hypothenuse,  the 
distance  the  back  of  the  blade  or  tongue  is  raised  forming  the  per- 
pendicular of  the  triangle,  which  requires  about  %  inch  less  than 
the  widdi  of  the  square  as  a  base  in  order  to  give  the  correct 
"draw"  to  the  tenon. 

A  UNIVERSAL  LAYING-OUT  GAGE. 

While  gages  as  shown  by  Fig.  37  are  particularly  desirable 
for  work  where  one  or  two  sizes  of  timber  are  to  be  framed, 
the  writer  prefers  several  gages  of  that  kind,  but  each  one  made 
for  a  single  size  of  mortise  or  dap — particularly  for  flume  fram- 
ing, for  barn  work,  or  where  there  are  to  be  many  mortises  or 
daps  of  the  same  shape  and  size  in  timbers  of  the  same  size. 


ERECTION  OF  BUILDINGS 


107 


For  universal  work,  particularly  for  jobs  where  there  are  many 
mortises  or  daps  in  all  sorts  and  kinds  of  timbers,  the  writer  uses 
a  gage  which  he  made  for  that  purpose,  as  shown  by  Fig.  40. 

This  tool  is  simply  a  sheet  of  hard,  or  half-hard  brass,  a 
little  more  than  1/16  inch  thick,  12  inches  long,  18  inches  wide, 
and  bent  to  95  degrees  as  shown  by  the  engraving.  The  sheet  is 
not  bent  in  the  middle,  but  one  leg  is  made  wider  than  the  other 
so  that  side  c  will  be  as  wide  as  the  largest  timber  to  be  marked. 
One  edge  of  the  tool  is  graduated  at  c  into  inches,  halves  and 
quarters,  and  a  small  hole  is  drilled  at  the  end  of  each  line  form- 


FIG.   40.— UNIVERSAL  LAYING-OUT  GAGE. 

ing  the  graduation,  as  shown.  When  a  mortise  or  a  dap  is  to 
be  marked  out,  the  end  of  the  tool,  d,  is  brought  to  the  line 
where  the  cutting  is  to  start  and  a  line  is  marked  across  the  timber, 
using  the  end  of  the  brass  tool  as  a  straight-edge  or  square. 

To  draw  the  longitudinal  lines,  the  scratch-awl  or  pencil  point 
is  placed  in  one  of  the  holes  c,  d,  e,  f,  or  g,  according  to  the  dis- 
tance from  the  edge  that  it  is  desired  to  draw  the  dap  line  or 
the  tenon  or  mortise  line.  As  may  be  seen,  even  inches  are  drilled 
at  d,  half  inches  at  e,  and  the  quarter  inches  on  the  other  end  of 
the  tool  at  /  and  g.  With  the  scratch  or  pencil  in  one  of  these 


108  MILLWRIGHTING 

holes,  the  tool  is  given  a  lengthwise  movement  on  the  timber  and 
works  exactly  as  if  it  were  a  scratch-gage.  The  handle  a  is 
riveted  in  place,  countersunk  holes  being  made  for  the  rivets  so 
that  the  tool  will  be  perfectly  smooth  inside. 

The  great  objection  to  this  tool  is  the  liability  of  making 
wrong  marks  owing  to  the  numerous  holes  through  which  the 
scratch  may  be  thrust.  But  as  the  tool  is  not  as  bad  in  this  respect 
as  the  steel  square,  that  point  cannot  be  brought  against  it.  To 
mark  the  foot  of  the  mortise,  the  scratch  is  placed  in  that  one  of 
the  c  holes  which  represent  the  length  of  the  mortise  when  end 
d,  e,  is  on  the  head  line  of  the  mortise,  which  is  the  first  position 
of  the  tool.  If  the  mortise  or  dap  is  to  be  8  inches  long,  the  line 
is  squared  across  by  drawing  the  scratch  or  pencil  along  c,  then 
the  scratch  is  pressed  down  into  hole  c8,  the  tool  moved  one  side 
until  the  scratch-point  mark  is  found,  then  the  scratch  is  replaced 
in  that  mark,  the  tool  up  against  the  scratch,  and  the  foot  line 
of  the  mortise  is  struck  across  the  face  of  the  timber. 

WORKING  FROM  "THE  FACE  CORNER/' 

/ 

When  a  millwright  starts  to  lay  out  a  stick  of  timber,  the  first 
thing  which  should  be  done  is  to  select  the  working  corner  of  the 
stick  and  to  mark  that  corner  in  a  manner  easily  distinguished 
from  other  corners  of  the  timber.  Usually  a  single  line  is  made 
on  each  of  the  two  best  sides  of  the  timber,  the  marks  meeting 
on  the  corner  which  is  to  be  taken  as  the  work  corner.  This 
method  of  marking  is  shown  at  e,  Fig.  36,  and  in  framing  that 
timber  the  square  or  gage  should  never  be  applied  to  other  than 
the  marked  sides  e  and  c.  That  is,  the  tools  should  never  be 
applied  to  other  than  the  two  sides  in  question  for  the  purpose  of 
squaring  a  line  around  that  timber. 

SQUARING  AROUND  A  TIMBER. 

The  matter  of  squaring  around  a  timber  is  shown  by  Fig.  41, 
both  the  right  and  the  wrong  methods  being  shown.  The  best 
face  is  first  selected  and  marked  a,  then  the  next  most  desirable 
side  is  selected  and  marked  as  at  b.  Squaring  around  the  timber 
is  commenced  by  placing  the  square  at  d  and  making  a  fine  mark 
across  the  face  b  of  the  timber ;  then  the  square  is  placed  as  shown 
at  c  and  another  line  struck  down  the  back  side  of  the  timber. 


ERECTION  OF  BUILDINGS 


109 


So  far  so  good,  and  the  operation  is  correct.  Next,  the  square  is 
placed  at  e,  which  is  wrong,  as  will  be  developed  later.  The 
pencil  is  used  on  the  bottom  of  the  timber  and  the  square,  placed 
at  /,  is  brought  to  the  line  on  the  bottom  of  the  timber.  As 
will  be  seen  at  g,  the  lines  d  and  f  do  not  come  together  on  the 
corner  of  the  timber,  and  it  is  evident  that  something  is  wrong. 
Had  the  timber  been  perfectly  parallel  or  one  end  as  wide  as  the 
other  side  the  lines  would  have  come  together  on  the  last  corner, 
no  matter  how  the  squares  were  placed,  but  when  the  timber  is 
wedge-shaped  in  one  or  more  directions  it  is  impossible  for  the 
lines  to  meet  when  the  squares  were  used  as  at  c,  d,  e  and  /. 


FIG.  41.— SQUARING  AROUND  A  TIMBER. 

To  prevent  such  a  happening,  always  apply  the  squares  on 
the  marked  faces  of  the  timber,  as  shown  at  the  right  of  Fig.  41. 
Never  place  the  blade  of  the  square  against  other  sides  than 
a  and  b  and  there  never  will  be  trouble  from  lines  not  meeting. 
As  shown,  place  the  squares  at  h  and  i,  marking  as  when  they 
were  at  d  and  ct  which,  as  stated,  is  all  right.  Next,  instead  of 
rolling  the  timber  ahead  and  applying  the  square  at  e,  c,  roll  the 
timber  backwards  and  place  the  square  at  k,  bringing  it  even  with 
the  mark  made  when  the  square  was  at  i.  The  mark  having  been 
made  along  the  square  at  /,  reverse  that  instrument  again  and 
place  it  with  the  blade  on  face  b  again,  as  shown  at  h.  With  the 
tool  in  this  position,  the  line  to  be  struck  across  side  a  of  the 


110  MILLWRIGHTING 

timber  will  come  fair  with  the  first  line  made  at  h.  If  the  lines 
do  not  come  fair  with  each  other,  the  trouble  is  in  not  holding  the 
square  properly  or  in  not  meeting  the  lines  on  all  sides  of  the 
timber.  The  trouble  is  not  from  the  cause  which  gave  trouble 
at  g. 

TAKING  TIMBER  OUT  OF  WIND. 

When  timber  has  not  been  squared  up  at  the  mill,  it  is  some- 
times necessary  for  the  millwright  to  take  a  stick  "out  of  wind." 
That  is  he  must  make  both  ends  of  a  given  side  of  a  timber 
line  up  with  each  other.  A  method  of  performing  this  opera- 
tion is  illustrated  by  Fig.  42.  When  the  square  is  placed  upon  this 
timber,  it  is  found  that  at  end  b  the  square  when  held  firmly  to 
side  a  d  strikes  the  timber  at  the  corner  b,  but  is  open  on  the 
other  side  of  the  stick.  At  the  other  end  of  the  timber,  it  is 


FIG.    42.— SIGHTING   AND   SPOTTING   TIMBER   OUT   OF  WIND. 

found  that  the  square  hits  the  wood  at  the  far  end  of  the  blade, 
near  /.  Should  two  squares  be  placed  as  shown  at  e  and  /,  or 
two  parallel  pieces  of  wood  be  thus  placed,  the  eye,  sighting 
from  d  over  the  two  squares,  will  discover  that  they  are  not  par- 
allel with  each  other,  that  one  runs  up-hill,  the  other  down,  exactly 
as  the  timber  is. 

To  remedy  the  defect,  hew  or  chisel  off  the  surface  of  the 
timber,  as  shown  at  b  until. the  square  will  hang  fair  on  &,  also  on 
side  a  d.  Next,  perform  the  same  operation  at  c,  but  here  the  cut 
will  be  found  on  the  opposite  side  of  the  timber,  and  the  cutting 


ERECTION  OF  BUILDINGS  111 

must  be  done  until  the  squares  are  in  line,  as  determined  by  the 
eye  at  g,  not  by  making  the  square  fit  sides  c  and  ad.  If  the  latter 
named  side  fits  the  tongue  of  the  square  after  the  timber  is  spotted 
off  at  c,  then  so  much  the  better,  and  we  know  that  side  a  d  is  in 
line  as  well  as  side  b  c.  But  if  side  a  d  does  not  fit  square  /  when 
that  tool  is  lined  up  with  square  e,  then  there  is  a  chance  for  a 
little  cutting  on  side  a  d  as  well  as  at  b  c. 

"BOXING,"  OR  CUTTING  "DAPS." 

When  the  framing  is  done  at  the  mill,  "boxing"  or  "dapping" 
is  either  done  by  large  dado-heads  or  the  timber  is  placed  upon 
a  Daniels  planer  and  the  greater  part  of  the  cutting  done  by  that 
machine,  after  which  the  work  is  finished  by  hand.  The  dado- 
head  method  is  by  far  the  best,  and  if  the  mill  does  not  contain 
such  a  tool  a  special  machine  should  be  rigged  up  for  that  pur- 
pose. But  in  cutting  daps  by  hand  the  method  used  should  be 
according  to  that  shown  by  Fig.  43. 


FIG.   43.— "BOXING"   OR   CUTTING   "DAPS." 

The  dap  having  been  laid  out  as  described  in  a  preceding  para- 
graph, a  saw-cut  is  made  just  inside  the  line  at  either  end,  as 
shown  at  a,. Fig.  43.  Two  methods  are  followed:  Either  several 
saw-cuts  are  run  down  to  the  line  a,  and  the  wood  between  the 
cuts  removed  with  the  mallet  and  chisel  or  the  adze ;  or  the  latter 
tool  may  be  employed  as  soon  as  the  two  end  saw-cuts  have  been 
made.  As  shown  at  b,  the  wood  inside  the  marks  has  been  scored 
deeply  with  adze  or  ax  and  is  ready  to  be  roughly  removed,  either 
by  means  of  the  adze  or  with  mallet  and  chisel  until  a  plane  can 
be  used  on  the  bottom  of  the  cut. 


112 


MILLWRIGHTING 


A  rebate  plane  may  be  used  next  to  the  walls  of  the  dap  and 
a  fore  plane  or  a  short  jointer  is  the  proper  tool  for  finishing  the 
rest  of  the  surface.  At  c,  Fig.  43,  the  dap  is  shown  half  finished, 
and  a  tool,  d,  is  shown  in  position  for  work.  This  tool  is  a  very 
useful  addition  to  the  millwright's  kit  and  it  is  worth  many  a 
dollar  for  cutting  the  wood  out  of  grooves  in  the  bottom  of  tank 
staves,  the  dadoed  ends  of  water  tanks,  or  for  similar  work.  This 
tool  will  be  described  in  the  next  paragraph,  and  it  is  only  neces- 
sary to  state  here  that  the  long  wooden  bar  is  grasped  with  the 
hands  and  pushed  back  and  forth,  the  little  tool  slicing  off  the 


FIG.  44.— "DAPPING"  OR  "BOXING"  TOOL. 

wood  above  the  depth  to  which  the  tool  is  set,  and  it  follows  the 
grain,  dodging  around  knots  or  tough  places  in  a  most  con- 
siderate manner  until  the  entire  surface  has  been  cleaned  off 
as  shown  at  e,  all  ready  for  the  plane. 

This  tool,  the  use  of  which  was  noted  above,  is  shown  more 
in  detail  by  Fig.  44.  It  is  usually  made  of  a  piece  of  hard  wood, 
maple,  beech  or  hickory  as  may  be  obtainable.  A  piece  about 
2x2%  inches  answers  very  well,  though  the  size  may  be  varied 
.to  suit  the  work  to  be  done.  The  length  of  the  wooden  bar 
must  be  a  little  more  than  twice  the  length  of  the  longest  dap 
to  be  made.  This  is  necessary  that  the  bar  may  at  all  times  have 
a  bearing  on  the  timber  adjacent  to  the  ends  of  the  dap,  and  as 


ERECTION  OF  BUILDINGS  113 

the  distance  from  the  cutter  to  either  end  of  the  bar  must  be  a 
little  more  than  the  length  of  the  dap,  the  rule  about  twice  the 
length  of  the  dap  holds  good  for  the  length  of  the  bar  in  all  cases. 

The  tool  b,  b  is  usually  made  from  %  inch  square  tool  steel, 
and  it  very  closely  resembles  one  of  the  cutting  tools  from  a 
Daniels  planer.  In  fact,  the  writer  has,  more  times  than  one, 
used  one  of  these  tools  for  the  cutter  in  a  dapping  tool,  making 
the  bar  a  to  fit  the  planer  tool,  a  hole  being  mortised  through 
the  bar  to  receive  cutter  b,  b,  and  a  wedge  c  made  to  fit  the  mor- 
tised hole  after  the  cutter  has  been  placed  inside  it. 

The  three-cornered  hole  is  cut  out  of  the  front  of  the  bar 
in  order  to  allow  room  for  the  chips  from  the  cutting  tool.  The 
tool  b  should  be  located  in  a  certain  position  relative  to  the  face 
of  the  bar,  as  indicated  by  the  dotted  lines  d  and  e.  The  former 
line  is  drawn  square  out  from  the  center  of  the  cutting  tool  to  the 
edge  of  the  bar,  thence  vertically  downward  across  the  face  c 
of  the  bar,  and  the  line  in  question  shall  intersect  the  center  of 
the  tool  as  shown.  The  dotted  line  e  represents  the  depth  to 
which  the  tool  has  been  set,  and  in  this  case  it  is  one-half  inch. 
The  bar  when  pushed  along  to  a  certain  line  will  stand  with  the 
cutting  edge  of  tool  b  exactly  on  that  line.  In  other  words,  the 
cutting  edge  of  tool  b  is  exactly  flush  with  the  front  side  of  bar  c. 

The  reason  for  this  particular  arrangement  is  that  when  using 
the  dap  tool  there  is,  when  a  heavy  cut  meets  the  tool,  a  very 
strong  possibility  of  the  tool  rocking  about  the  line  e;  and  if  the 
tool  were  long  enough  to  project  beyond  line  e,  it  would  dig  into 
the  bottom  of  the  dap  every  time  the  bar  tipped  up.  As  long 
as  the  cutter  does  not  project  beyond  *the  face  of  the  bar,  there 
is  no  possibility  of  its  catching  and  digging  into  the  work  when 
such  a  tip-up  occurs.  As  the  cutter  wears  away,  it  will  not 
reach  quite  to  the  line  e,  but  the  cutter  cannot  dig  into  a  flat 
surface  when  it  is  back  of  line  e,  so  the  shortening  of  the  tool 
does  no  harm. 


CHAPTER  VIII. 

WALLS  AND  MACHINERY  SUPPORTS. 

The  tendency  of  factory  design  and  construction  at  present 
is  to  carry  the  shafting  upon  the  timbers  of  the  building.  •  For 
main  shafts,  there  is  no  way  of  supporting  them  which  is  better 
than  a  line  of  solid  piers  built  strong  enough  to  carry  the  shaft 
and  to  withstand  the  pull  of  belts  and  the  strain  of  gears.  A  line 
of  solid  wooden  posts  makes  a  very  desirable  hanging  for  shaft- 
ing, and  beams  framed  between  posts  are  first-rate  for  shaft 
supporting,  provided  the  shaft  can  be  placed  on  top  of  the  timbers. 

DROP  HANGERS  vs.  PILLOW-BLOCKS. 

The  writer  has  found,  to  his  sorrow,  that  drop  hangers  are 
not  very  desirable  shaft  supports.  In  fact,  though  earlier  mills 
built  by  the  writer  contained  a  great  many  drop  hangers, 
the  later  designs  have  seldom  contained  any  hangers  whatever 
— not  more  than  one  or  two,  in  places  where  it  wras  not  convenient 
to  locate  pillow-blocks.  Aside  from  the  tendency  of  long  hangers 
to  sway  sidewise,  and  to  vibrate  more  or  less,  it  appears  very 
unmechanical  to  the  writer  to  put  all  the  pull  of  the  shaft  and 
its  belts  upon  a  bolt  where  the  nature  of  the  pull  tends  to  loosen 
the  hanger  instead  of  to  tighten  it. 

With  the  drop  hanger,  everything  depends  upon  the  bolt. 
Not  only  does  the  pull  of  the  belts  come  upon  the  bolts,  but  the 
weight  of  the  shaft  and  pulleys,  and  even  of  the  hanger  itself, 
must  be  carried  by  two  or  four  little  rods  as  large  as  the  finger. 
And  all  this  stuff  bears  upon  a  few  washers  which  proceed  to 
wear  themselves  into  the  timbers  upon  which  they  rest  the  instant 
the  mill  is  started — and  the  washers  continue  to  wear  into  the 
wood  and  to  have  their  bolts  constantly  screwed  tighter  as  long 
as  they  stay  in  commission. 

With  the  ball  and  socket  pillow-block,  the  weight  of  shafting, 
pulleys,  and  sometimes  the  pull  of  the  belts,  all  tend  to  hold  the 

114 


WALLS  AND  MACHINERY  SUPPORTS          115 

bearings  in  place  and  to  help  the  bolts,  instead  of  at  all  times  work- 
ing against  those  indispensable  little  workers.  Even  with  post 
hangers  the  arrangement  is  fairly  neutral,  for  with  the  belt 
pull  properly  arranged  the  bolts  have  little  more  to  do  than  to 
hold  the  hangers  to  their  posts  as  wedge  bearings  should  in  all 
cases  be  provided  underneath  the  post  hangers  in  such  a  manner 
that  even  were  the  bolts  to  go  loose  the  hangers  cannot  settle 
out  of  place. 

When  a  line  of  heavy  shafting  must  be  carried  on  a  wall  or 
on  a  line  of  posts,  what  appears  to  the  writer  as  an  ideal  arrange- 
ment for  that  purpose  is  to  erect  brackets  upon  wall  or  posts 
and  to  provide  lugs  enough  so  the  brackets  cannot  settle,  even 
should  the  bolts  go  slightly  loose.  Then  place  the  shaft  in -self- 
adjusting  pillow-blocks  fixed  on  top  of  the  brackets,  and  nothing 
better  can  be  asked  as  long  as  the  posts  or  the  wall  remains  rigid 
and  strong  enough  to  carry  the  load. 

SHAFTING  ON  BIN-SUPPORTS. 

In  arranging  to  support  a  line  of  shafting  upon  a  wall  or  a 
line  of  wall  posts  in  a  wooden  building,  the  millwright  should 
first  look  the  plans  over  carefully  to  see  wThether  there  are  cer- 
tain posts  which  are  to  be  subject  to  an  intermittent  load.  In 
some  mills,  there  are  storage  bins  or  floors  where  stock  is 
placed  upon  receipt  and  is  removed  as  required.  Such  posts  or 
timbers  as  support  the  bins  or  floors  are  very  poor  things  upon 
which  to  place  shafting. 

All  material  is  more  or  less  elastic,  even  glass;  and  wood  is 
especially  endowed  with  elasticity  and  yields  ta  pressure,  and  if 
not  loaded  beyond  its  elastic  limit  springs  back  again  when  the 
pressure  is  removed  by  the  unloading  of  bin  or  storage  floor. 
Shafting  attached  to  such  timbers  can  never  be  made  to  stay 
straight.  When  the  load  is  on,  the  timbers  are  sprung  out  of  line 
and  carry  the  bearings  with  them.  When  the  load  is  removed, 
the  bearings  take  another  position,  the  shaft  usually  goes  with 
the  bearings,  and  much  lost  power  is  the  result.  Whenever  a 
line  of  posts  is  met  with  which  are  subjected  to  loading  as  above, 
the  millwright  should  seek  other  supports  for  the  shafting.  Put 
in  separate  posts  to  carry  the  shafting,  placing  them  as  best  they 
can  be  placed,  and  if  possible,  put  in  independent  foundations 


116  MILLWRIGHTING 

for  the  shaft-supporting   timbers,   thereby  saving  much  future 
trouble  in  the  way  of  leveling  and  alining  the  shafting. 

WALLS  FOR  SUPPORTING  SHAFTING. 

When  shafting  can  be  attached  to  well  built  masonry  walls, 
there  is  usually  little  danger  of  distortion  by  the  springing  of 
the  wall,  provided  the  masonry  is  well  constructed  and  the  foun- 
dation ample  for  the  maximum  load  to  be  carried.  In  case 
masonry  does  yield  to  pressure  of  the  loaded  space  supported  by  it, 
there  will  be  little  return  to  the  original  position  after  the  load 
has  been  removed.  That  is,  while  the  timber  construction  springs 
back,  the  masonry  stays  where  the  load  left  it  and  after  the  foun- 
dations have  settled  to  their  ultimate  bearing  position,  the  load- 
ing and  unloading  of  a  masonry  wall  has  very  little  effect  upon  it, 
hence  the  desirability  of  masonry  for  shaft  supports. 

A-PiERs  FOR  LONG  SHAFTS. 

When  shafts  must  be  supported  to  pass  long  spans,  where 
there  is  nothing  but  the  weight  of  the  shaft  to  be  carried,  no 
pulleys  or  gears  to  cause  side-pull,  then  the  simple  A-frame  is 
ample  for  carrying  the  shaft.  Such  a  frame  is  shown  by  Fig.  45, 
two  timbers,  ranging  from  6x6  inches  to  12x12  inches  being 
used,  according  to  the  size  of  the  shaft  and  the  hight  at  which  it 
must  be  supported  above  the  ground.  In  the  engraving,  the  timbers 
a  and  b  are  bored  at  the  bottom  to  receive  pieces  of  steam  pipe 
which  serve  as  dowels  to  prevent  lateral  movement.  A  third  bit 
of  timber,  c,  is  framed  across  the  two  inclined  timbers  as  shown, 
and  this  short  piece  receives  the  bearing  which  supports  shaft  e. 

A  ys-inch  bolt,  d,  is  placed  as  shown  through  both  vertical 
timbers  below  c  to  hold  the  framing  together  at  the  head.  This 
arrangement  is  for  a  pillow-block  with  four  holding-down  bolts. 
When  there  are  but  two  bolts,  one  in  either  end  of  the  pillow- 
block,  put  in  two  %-inch  bolts  instead  of  one  %-inch,  and  there 
will  be  no  interference  with  the  bolts  or  their  heads  underneath 
block  c.  Bracing  is  put  on  the  frame  as  shown,  using  2x6-inch 
stuff,  and  some  ladder  cleats  and  a  platform  are  also  provided, 
the  latter  being  made  by  extending  one  of  the  climbing  cleats, 
which  was  made  very  heavy,  placing  a  similar  cleat  on  timber  a, 
and  connecting  the  cleats  by  a  couple  of  planks.  In  erecting  this 


WALLS  AND  MACHINERY  SUPPORTS 


117 


frame,  there  is  not  a  spike  in  it  except  where  timber  c  is  toe-spiked 
to  a  and  b  to  prevent  lateral  sliding.  The  fastenings  to  the  climb- 
ing cleats  and  the  braces  and  stays  are  all  ^x4^-inch  lag-screws 


FIG.  45.— A-FRAME  SHAFT  PIER. 

with  rolled  threads.  Washers  are  placed  under  the  heads,  and 
the  screws  set  up  tight — and  kept  tight  by  occasional  going  over 
and  screwing  up.  Wood  will  shrink,  and  screws  need  occasional 
tightening,  especially  with  new  timber. 

ERECTING  AN  A-FRAME  PIER. 

It  is  the  custom  of  the  writer,  when  an  A-frame  pier  must  be 
set  up,  to  build  the  thing  on  the  ground  and  to  set  it  up  afterward. 
If  the  shaft  is  already  in  place,  the  problem  is  an  easy  one,  all 
that  is  necessary  being  to  set  a  "shore"  under  the  shaft,  attach 


118  MILLWRIGHTING 

a  rope  or  chain  tackle  close  to  the  shore,  and  pull  the  top  of  the 
pier  into  position,  with  the  braces,  stays,  working  platform,  climb- 
ing cleats  and  "dowels  all  in  position.  Once  erected,  the  bear- 
ing is  bolted  to  the  shaft,  it  having  been  already  in  place  on 
timber  c;  then  the  pier  is  blocked  up  under  the  stays,  and  con- 
crete is  run  into  the  foundation  holes  around  the  pipe  dowels. 
By  placing  the  bearing  square  with  the  frame  and  adjusting  that 
so  the  shaft  hangs  fair  in  the  bearing,  no  other  adjustments  are 
needed  and  the  pier  will  be  in  correct  position  after  the  cement 
hardens  and  the  props  are  removed  provided  care  is  taken  to  have 
the  shaft  in  good  alinement  and  perfectly  level  before  the  concrete 
is  poured  and  rammed.  A  set-collar  on  either  side  of  the  pillow- 
block  holds  the  A-frame  from  moving  sidewise  or  lengthwise 
of  the  shaft  which  virtually  supports  the  A-frame  axially. 

PROPORTIONING  BOLTS  AND  RODS. 

In  describing  the  method  of  bolting  the  head  of  the  A-frame 
pier  it  was  stated  that  one  %-inch  or  two  %-inch  bolts  would 
do  the  work.  A  very  convenient  method  of  determining  the  num- 
ber of  bolts  or  rods  which  will  be  equal  in  strength  to  one  or  more 
bolts  of  a  different  diameter  is  as  follows : 

"Square  the  diameter  of  the  rod,  divide  or  multiply  by  the 
number  of  rods  to  be  substituted  and  find  the  square  root  of  the 
result." 

In  the  case  given  above  a  %-inch  bolt  was  to  be  replaced  by 
two  smaller  bolts,  but  which  possessed  equal  strength.  The  opera- 
tion is  as  follows : 

49          25  25 

%X%=^^2=—  nearly.     The  square  root  of  — = %,  the 

required  diameter. 

Supposing  it  was  necessary  to  replace  a  1-inch  bolt  with  two 

C*  A  *^O 

smaller  ones,  then:  8/8X8/8=^-^-2=^,  and  the  square  root 

64  64 

32 
°f  ^=6/8=%,  nearer  than  any  other  regular  size  of  iron.   The 

exact  diameter  of  bolt  would  be  — - -   -  inches=0.707  inches,  in- 

8 

stead  of  0.75,  as  called  for  by  the  nearest  diameter  of  stock  bolts. 
This  matter  is  graphically  shown  by  Fig.  46,  in  which  the  circle 


WALLS  AND  MACHINERY  SUPPORTS 


119 


b  represents  the  cross-sectional  area  of  a  bolt  1  inch  in  diameter. 
The  dotted  square  a  is  to  represent  the  area  derived  from  multi- 
plying the  diameter  by  itself — squaring  it — or  one  square  inch. 
In  dividing  by  2,  to  obtain  one-half  the  total  area,  the  sectioned, 
or  hatched  portion  c  is  taken,  and  carried  to  d,  where  a  rectangle, 
o  inch  is  shown,  hatched  as  before. 


FIG.    46.—  PROPORTIONING   BOLTS. 


The  shaded  section,  d,  represents  the  area  Ix^  inch, 


32 


square  inch.  In  order  to  get  this  area  into  the  form  of  a  square, 
its  root  is  extracted,  giving  the  square  area  £=0.707  inch  on  each 
side,  and  the  inscribed  circle  /  represents  the  size  of  a  bolt  one-half 
the  size  of  the  1-inch  bolt.  For  comparison,  the  circle  /  is  laid 
down  at  g,  inside  the  1-inch  diameter.  When  it  is  desired  to 
ascertain  the  size  of  one  or  more  bolts  to  equal  the  strength  of 
several  smaller  bolts,  then  the  process  is  reversed.  For  instance  : 
What  diameter  of  bolts  must  be  used,  in  place  of  i/^-inch  bolts,  in 
order  that  two  bolts  may  be  equal  in  strength  to  six  i/o-i 


bolts?     %X%=1/4X6=— ,  the  square  root  of  — -5-2=.J  %= 

w 


— -==%  inch  nearly.    Or,  two  %-inch  bolts  will  do  the  work. 

One  point  which  will  be  neglected  in  all  these  calculations  is 
the  fact  that  the  smaller  the  rod,  the  greater  the  strength  to  the 
square  inch  of  cross  section.  This  may  be  noted  in  the  table  (II) 
giving  the  strength  of  Ransome  bars.  While  bolts  may  be  taken 
as  having  a  strength  of  about  60,000  pounds  to  the  square  inch 
of  cross  section,  the  same  steel,  when  drawn  into  wire,  will  be 
found  to  possess  a  strength  about  double  that  figure,  often  run- 
ning up  to  125,000  to  128,000  pounds  to  the  square  inch.  But 


120 


MILLWRIGHTING 


this  point,  as  stated,  is  neglected  in  the  calculations.  It  is  men- 
tioned that  the  millwright  may  have  some  understanding  of  why 
small  rods  and  wire  seem  stronger  than  larger  sections.  They  are 
stronger  and  will  carry  more  load  safely. 

ROLLED-THREAD  LAG-SCREWS. 

It  was  stated  in  connection  with  the  A-frame  pier  that  rolled- 
thread  lag-screws  were  particularly  desirable  and  should  be  used 
in  preference  to  those  having  the  thread  cut  in  the  usual  man- 
ner. Fig.  47  represents  the  two  forms  of  lag-screws,  and  it  will 
be  noted  that  in  sketch  A  the  body  of  the  screw  maintains  its 
size  the  entire  length  of  the  screw,  both  in  shank  and  in  the  thread. 
This  is  the  rolled-thread  type.  Besides  possessing  more  strength 


FIG.    47.— ROLLED-THREAD    LAG-SCREWS. 


than  the  old  form  of  lag-screw,  it  has  the  advantage  that  only  one 
bit  is  necessary  for  applying  this  lag-screw,  while  the  old-fash- 
ioned form  of  lag-screw,  shown  by  B,  must  have  two  bits,  one 
for  the  shank,  the  other  for  the  threaded  portion,  in  order  to  get 
it  into  place. 

These  lag-screws  are  so  proportioned  that  they  weigh  about 
the  same,  though  the  new  form,  A,  appears  to  be  the  heavier.  To 
prevent  this,  the  shank  or  body  of  lag-screw  A  is  rolled  a  trifle 
smaller  than  its  nominal  size — just  enough  smaller  so  that  it  will 
follow  the  bit  of  that  size.  Thus  instead  of  having  to  use  a  body 
bit  of  17/32  or  9/16  inch,  the  size  of  the  body  is  made  just  small 
enough  so  that  it  will  slide  through  a  ^-inch  hole.  Probably  the 
shank  is  a  little  more  than  15/32  inch  in  diameter.  The  great 
objection  to  this  form  of  lag-screw  is  that  a  much  larger  washer 
is  required,  a  %-inch  washer  being  necessary  unless  the  mill- 


WALLS  AND  MACHINERY  SUPPORTS  121 

wright  is  willing  to  screw  the  entire  length  of  thread  through  the 
washer,  in  which  case  the  ordinary  y2-inch  size  may  be  used. 

FLOORS  AND  FLOORING. 

Beyond  all  doubt  the  slow-burning  mill  construction  floor  is 
the  best  yet  devised  for  general  factory  use,  owing  to  the  fact 
that  machinery  can  be  located  anywhere  it  is  desired  to  place  it 
without  having  to  reinforce  the  floor  under  which  the  machines 
stand.  This  of  course  does  not  apply  to  excessively  heavy 
machines  which  require  a  special  foundation  of  their  own. 

There  must,  however,  be  one  exception  to  the  slow-burning 
floor  type,  for  undoubtedly  the  floor  built  of  reinforced  concrete 
stands  over  everything  else  in  the  floor  line  for  the  placing  of 
machinery.  The  millwright  is  confronted  with  entirely  new  con- 
ditions when  he  is  called  upon  to  erect  machinery  and  to  hang 
shafting  upon  concrete  walls  and  floors,  and  methods  of  working 
the  new  conditions  will  be  discussed  elsewhere  in  this  book. 

LAYING  "SLOW-BURNING"  FLOORING. 

The  methods  of  laying  flooring  vary  so  greatly  according  to 
the  material  used  that  it  would  require  a  volume  to  give  full 
instructions  concerning  that  part  of  mill  construction,  consequently 
the  description  of  any  floor  construction  that  can  be  given  here 
must  be  very  brief  indeed.  With  heavy  plank  floors,  such  as  those 
for  slow  burning  construction,  it  is  best  to  lay  one  plank  at  a 
time,  running  the  pieces  one  after  another  the  entire  length  of 
the  building,  and  breaking  joints.  Each  plank  should  be  squeezed 
tightly  against  the  finished  portion  of  the  floor  on  every  beam, 
and  the  proper  fastenings  put  in  before  the  leverage  is  removed. 

A  number  of  types  of  floor  clamps  are  in  the  market,  and  it  will 
pay  to  secure  two  or  more  of  these  clamps  and  use  them  instead 
of  nailing  on  cleats  or  ledgers  at  every  beam  for  each  plank  in 
order  to  provide  a  bearing  for  the  wedges  or  levers  with  which 
the  planks  are  forced  into  place. 

LAYING  1-  AND  2-iNCH  FLOORS. 

When  common  %-inch,  random  width  flooring  is  to  be  laid, 
the  workman  usually  fits  a  section  six  or  seven  feet  wide  and  of 
any  length  which  the  boards  will  reach.  Then  the  outer  board 


122  MILLWRIGHTING 

is  moved  inwards  from  %  to"1/^  inch  and  fastened  by  a  few  nails 
driven  partly  in,  as  shown  at  b,  b,  Fig.  48.  In  placing  the  flooring 
for  this  operation,  the  boards  are  all  laid  side  by  side  as  closely  as 
'possible,  the  marks  a,  a  made  on  the  floor  beams,  then  the  middle 
pair  of  boards  c,  d  are  removed  and  the  outer  boards  moved  back 
from  the  marks  a,  a  the  required  distance,  and  fastened  tempo- 
rarily as  noted.  Some  mechanics  drive  the  nails  home,  but  it 


FIG.    48.— LAYING    %-INCH    FLOORING. 

is  better  to  leave  the  nails  so  they  may  be  drawn  in  case  more  or 
less  crowding  is  necessary  for  the  section  of  flooring.  The  boards 
c,  d  being  placed  as  shown,  one  or  two  pieces  of  board,  e,  are 
thrown  crosswise  of  the  section,  and  with  a  man  or  two  on  each 
cross-board,  boards  c  and  d  are  forced  down  into  place.  The 
"knuckle-joint"  action  of  the  boards  in  question  results  in  pla- 
cing a  considerable  strain  upon  the  boards  and  squeezing  them  into 
place  as  closely  as  if  they  had  been  clamped  with  the  most 
improved  appliances  in  the  market. 

SPRINGING  2-iNCH  PLANKS  INTO  PLACE. 

Sometimes  2-inch  plank  are  handled  in  the  manner  described 
above,  but  it  is  hard  work  and  requires  more  men  to  force  the 
tilted  planks  down  into  place.  When  the  boards  or  planks  go 
down  hard,  a  piece  of  2x4-inch  scantling  may  be  made  to  help 
a  great  deal  by  cutting  such  a  piece  in  between  any  convenient 
overhead  support,  and  the  board  e,  as  shown  at  /.  By  pulling 


WALLS  AND  MACHINERY  SUPPORTS  123 

against  f,  about  in  the  middle  of  its  length,  it  can  be  forced  into 
place  with  the  ends  vertically  above  one  another,  and  when  the 
pressure  is  released  at  the  middle  of  the  scantling,  its  elasticity 
will  cause  it  to  straighten  out  with  great  force,  pressing  down 
the  boards  with  many  hundred  pounds  pressure  and  holding  all 
the  gain  obtained  by  the  workmen  pressing  on  board  e.  This 
arrangement  is  very  useful,  particularly  when  forcing  a  heavy 
plank  floor  into  place. 

LAYING  TONGUED  AND  GROOVED  FLOORING. 

The  method  shown  by  Fig.  48  can  be  used  to  a  certain 
extent  with  tongued  and  grooved  flooring,  but  the  results  are  not 
very  satisfactory  and  there  is  great  danger  of  breaking  off  the 
upper  edge  of  the  grooved  side  as  all  the  pressure  comes  upon 
the  thin  portion  of  the  flooring  strips,  especially  in  the  pieces  c, 
d,  and  those  adjacent  to  them  on  either  side.  When  tongued 
and  grooved  flooring  is  to  be  handled,  it  is  better  to  run  it  in 
one  strip  at  a  time  the  entire  length  of  the  building,  in  the  man- 
ner described  for  slow-burning  floors,  except  that  the  clamps 
will  be  unnecessary,  the  strips  which  are  quite  narrow  being 
pressed  against  the  body  of  the  floor  with  a  common  chisel, 
the  end  of  which  is  driven  into  the  floor  beam.  Pressure  is  given 
at  each  nailing  which  is  "blind,"  and  the  results  of  this  method 
are  excellent,  provided  the  flooring  is  all  gotten  out  to  the  same 
width. 

WOOD  FLOORS  ON  CONCRETE  CONSTRUCTION. 

Skin  floors  %-inch  thick  are  frequently  placed  upon  rein- 
forced concrete  construction  in  the  manner  described  above. 
Usually  the  skin  floors  are  fastened  to  2-inch  pieces  put  the 
proper  distance  apart  for  nailing  strips,  and  filled  in  between 
with  cinder  concrete,  made  about  1,  2,  3.  The  wooden  nailing 
strips  are  sometimes  called  "screeds"  and  are  usually  made  wider 
at  the  bottom  than  on  top  so  as  to  dovetail  into  the  cinder 
concrete. 

HANGING  SHAFTING  TO  CONCRETE  WORK. 

When  concrete  construction  is  designed  for  supporting  shaft- 
ing, the  necessary  attachments  for  shaft  hangers  may  be  easily 


124  MILLWRIGHTING 

provided,  but  when  shafting  is  to  be  placed  in  a  building  already 
constructed,  then  the  problem  is  much  more  difficult  and  is  of 
an  entirely  different  nature.  Two  methods  are  shown  by  the  fol- 
lowing engravings,  and  either  may  be  adapted  to  his  needs  by 
the  millwright  as  the  conditions  may  demand. 

Fig.  49  illustrates  one  method  of  hanging  shafting  when 
planned  for  at  the  time  the  building  is  erected.  It  will  be  noted 
that  I-beams  are  placed  in  position  to  receive  the  journal  bearings, 
and  that  the  I-beams  are  bolted  to  the  concrete  work.  Several 
methods  may  be  followed  for  fastening  the  beams,  the  method 
shown  at  a,  b,  c  being  the  placing  of  three  bolts  in  the  forms  when 
the  concrete  is  rammed,  the  upper  end  of  each  bolt  having  been 
turned  over  as  shown  at  m,  thus  arranging  for  a  firm  hold  against 
the  concrete.  Sometimes  ordinary  bolts  are  used  and  cast  washers 
are  put  on,  forming,  in  fact,  inverted  anchor  bolts. 

If  desired,  an  inverted  U-Bolt  may  be  used  and  placed  as  at 
d,  e,  the  upper  end  of  the  U  passing  over  and  through  the  floor 
beam  n,  which  sustains  the  weight  of  the  I-beams  and  shaft  at 
that  end  of  the  transmission.  At  another  place  it  may  be  conve- 
nient to  hang  the  I-beams  directly  against  the  floor-beams,  instead 
of  under  the  girder-beams.  In  this  case  it  may  be  profitable  to 
put  in  three  "sky"  bolts  (they  may  thus  be  designated  to  dis- 
tinguish them  from  anchor  bolts),  as  shown  at  /,  and  attach 
the  I-beams  by  means  of  the  block  and  clips  shown  at  /.  Again, 
as  at  g,  it  may  be  convenient  to  build  one  end  of  the  I-beams 
directly  into  the  wall  and  secure  them  in  that  manner. 

WALL  HANGERS  AND  BRACKETS. 

As  stated  elsewhere,  drop  hangers  do  not  fully  fill  the  bill 
for  hangings  of  heavy  shafting,  and  where  the  shaft  can  be  placed 
near  a  wall,  or  against  piers,  the  method  shown  at  h  may  be 
found  convenient.  As  many  wall  brackets  are  provided,  as  shown 
at  i,  as  may  be  necessary  to  carry  the  shaft.  In  the  engraving, 
the  bracket  is  shown  directly  under  one  of  the  girder-beams  so 
as  to  take  advantage  of  the  heavy  concrete  in  the  wall  at  that 
point.  The  curtain  walls  may  be  heavy  enough  to  carry  wall 
brackets,  but  when  they  can  be  placed  in  line  with  the  heavy  con- 
struction it  should  be  done.  The  brackets  should  each  have  a 
projection  cast  upon  them  to  enter  the  cavity  /,  which  is  cored 


WALLS  AND  MACHINERY  SUPPORTS  125 

out  of  the  wall  to  receive  the  projecting  lug.  This  will  prevent 
all  settling  or  sliding  of  the  bracket  should  the  nuts  work  loose 
on  the  bolts  /,  k,  I,  which  are  built  into  the  wall  in  much  the  same 
manner  as  described  for  the  "sky"  bolts.  The  bracket  shown 
bolted  in  place  at  i  is  made  with  a  cored  top  in  order  that  the 
pillow-block  may  be  slipped  into  position  and  held  in  place  by 
means  of  T-head  bolts. 

In  all  applications  of  shaft  bearings  to  concrete  walls  and 
floors  (and  to  brickwork  too,  for  that  matter),  the  writer  is  very 
strongly  in  favor  of  placing  an  elastic  member  somewhere  in  the 
carrying  mechanism  between  shaft  and  concrete.  A  piece  of 
wood  from  y2  to  2  inches  thick,  placed  between  the  pillow-block 
and  the  bracket  or  steel  supports,  will  cause  the  machinery  to 
run  with  less  vibration.  It  seems  to  absorb  many  of  the  little 
shocks  and  jars,  and  the  nuts  do  not  come  off  nearly  as  fre- 
quently when  there  is  a  piece  of  wood  in  the  connections  as  they 
do  when  the  bearings  are  screwed  solid,  iron  to  steel. 

METHODS  OF  FASTENING  I-BEAMS. 

It  may  be  seen  at  a,  b,  c  that  a  single  flat  piece  of  iron  is 
used  for  fastening  the  I-beams  against  the  concrete  girder-beams. 
At  e  it  will  be  noted  that  the  I-beams  are  supported  by  two  short 
pieces  of  channel  shape,  which  are  in  turn  riveted  to  the  I-beams. 
At  /  a  shoe  is  used  which  may  be  fastened  to  the  I-beams  either 
by  small  bolts  tapped  through  the  flanges  of  the  beam  and  into 
the  shoe,  or,  as  shown  in  Fig.  49,  clips  may  be  used  which  are 
forced  by  the  bolts  firmly  against  the  I-beams,  clamping  them 
as  in  a  vise.  In  one  instance,  at  least,  the  writer  has  seen  cast- 
ings used  for  this  purpose  which  closely  resembled  the  old- 
fashioned  "chairs"  used  under  steam  railroad  rails  before  fish 
plates  were  used.  The  chairs  were  tightened  against  the  I-beams 
by  driving  a  wedge  which  clamped  the  beam  fast  to  the  chair. 

HANGING  SHAFTING  TO  OLD  REINFORCED  CONCRETE. 

The  examples  given  above  refer  mostly  to  new  work,  when  the 
necessary  bolts  and  fastening  may  be  put  in  place  during  the 
construction  of  the  building.  There  are,  however,  many 
instances  where  it  is  necessary  to  put  up  shafts  upon  old  concrete 


1126 


MILLWRIGHTING 


work,   either   in  making   changes   or   for   shafting   in   buildings 
not  originally  intended  for  mill  use. 

In  cases  of  this  kind  it  is  necessary  to  make  the  best  of  it, 
and  to  get  out  of  the  work  with  as  little  labor  as  possible  con- 
sistent with  safety,  good  work  and  the  desired  results.  The 
hangers  must  be  bolted  to  the  concrete  beams,  and  bolts  must 
have  holes ;  furthermore,  it  is  no  fun  drilling  holes  through 
concrete,  to  say  nothing  of  reinforced  concrete.  Supposing 


FIG.    49.— HANGING    SHAFTING    ON    REINFORCED    CONCRETE. 

holes  were  started  down  through  beam-girder  m,  for  a  bolt  a,  b 
or  c.  In  case  of  old  work,  nobody  knows  exactly  the  position 
of  the  stress  rods  p,  and  the  drill  is  liable  to  come  plump  upon 
one  of  those  pieces  of  reinforcing ;  therefore  it  is  best  to  use 
the  method  shown  at  d,  Fig.  49,  avoid  the  beams  and  the  girders, 
and  drill  through  the  floor  only,  and  obtain  the  necessary  hold- 
ing strength  for  the  bolts  by  straddling  one  of  the  beams  or  one 
of  the  girder-beams. 

BEAMS  AND  GIRDERS. 

Lest  there  be  a  misunderstanding  regarding  the  use  of  the 
terms  "beam"  and  "girder,"  it  will  here  be  stated  that  by  "beam"  is 
to  be  understood  that  portion  of  the  framing,  either  in  wood, 


WALLS  AND  MACHINERY  SUPPORTS 


127 


steel  or  concrete,  which  carries  the  floor,  or  would  carry  a  floor 
were  one  to  be  put  in.  Thus,  in  Fig.  49,  the  portion  of  the 
framing  represented  by  n  is  a  beam  pure  and  simple. 
The  large  timbers,  m  and  o,  are  beams  in  one  sense  of  the  word, 
inasmuch  as  they  carry  some  of  the  floor  directly.  Were  these 
timbers  to  be  dropped  beneath  the  regular  floor  beams,  so  that 
n  and  the  rest  of  that  class  of  beams  were  carried  on  top  of  m 
and  o,  then  those  timbers  would  be  "girders,"  and  so  designated. 
In  the  form  of  construction  shown  by  Fig.  49,  the  timbers  in 
question  do  the  Work  of  both  girders  and  beams,  hence  the  title 
applied  to  them  "beam-girders." 

A  YOKE-CLAMP. 

The  device  shown  by  Fig.  50  has-  been  used  by  the  writer 
a  number  of  times  when  erecting  shafting  in  an  old  building  of 
reinforced  concrete.  Two  holes  are  first  made  through  the 
floor,  they  are  laid  out  to  straddle  both  the  beam  and  the  I-beams, 
as  at  a  and  b.  The  U-strap  c  is  made  of  flat  iron  (soft  steel,  there 


FIG.    50.— A  YOKE-CLAMP. 

is  no  iron  nowadays  unless  it  is  made  to  order)  about  %x2  to 
%x3  inches,  according  to  the  load  to  be  carried.  The  ends  of 
the  strap  are  drawn  out  and  threaded  for  nuts.  If  there  are 
bolt-ends  at  hand,  it  will  pay  to  weld  some  to  the  flat  iron, 
instead  of  drawing  it  down  and  threading,  as  shown  at  d. 


128  MILLWRIGHTING 

The  yoke  e  is  made  from  two  pieces  of  channel,  a  couple  of 
holes  are  drilled  through  each  and  bolts  put  through  as  shown; 
then  the  I-beams  /  are  put  in  position  and  the  nuts  on  the  straps 
are  run  up  until  there  is  only  about  one  inch  play  between  the 
I-beams  and  the  floor-beams,  It  will  be  noted  that  the  strap  has 
been  cut  into  the  concrete  floor  at  c.  This  may  not  be  neces- 
sary in  some  instances,  and  where  there  is  no  necessity  for  a 
smooth  floor,  the  cutting-in  may  be  omitted. 

But  whether  the  strap  is  cut  in  or  left  on  top  of  the  floor  the 
procedure  is  the  same.  After  the  nuts  have  been  set  up  within 
an  inch,  as  directed,  push  strap  c  up  as  far  as  it  will  go,  holding 
it  by  a  bit  of  board  placed  under  one  of  the  threaded  ends,  and 
let  one  man  hold  the  strap  thus  while  another  man  dashes  some 
freshly  mixed  and  quite  thin  cement  mortar  into  the  channel 
cut  in  the  floor  for  c.  The  mortar  should  be  either  neat  cement 
or  made  with  very  fine  sand,  and  as  soon  as  it  has  been  thrown 
in  under  the  strap — the  concrete  surface  having  been  thoroughly 
wet  first — the  strap  is  dropped  into  place  and  the  nuts  quickly 
screwed  up  tight.  The  cement  will  be  forced  from  under  the 
strap  until  the  metal  has  obtained  a  good  and  solid  bearing  along 
the  entire  width  of  the  floor-beam.  The  holes  in  the  floor  are 
then  flushed  with  the  rich  mortar,  which  is  smoothed  off  where- 
ever  it  protrudes  from  the  concrete  surface,  and  when  the  cement 
has  set  there  will  be  one  shaft  bearing  which  will  never  get 
loose  through  shrinkage  of  wood.  Some  thin  cement  may  be 
placed  between  the  I-beams  and  the  bottom  of  the  concrete  with 
good  results,  and  the  screwing  up  of  the  nuts  will  force  out  all 
of  that  mortar  which  is  not  necessary  to  give  a  perfect  bearing 
to  the  I-beams. 

ERECTING  WALL  BRACKETS. 

Wall  brackets  placed  on  old  or  finished  new  concrete  must 
have  the  holes  drilled  through  the  wall.  There  is  no  get-away 
from  that  operation.  It  does  not  pay  to  put  in  expansion  bolts 
for  holding  shaft  timbering.  A  good  expansion  bolt  may  hold, 
but  the  millwright  does  not  know  whether  it  will  or  not.  He 
does  know  that  there  is  a  chance  for  expansion  bolts  to  fail, 
therefore  he  will  not  risk  having  a  shaft  come  down  by  using 
doubtful  holding  power. 


WALLS  AND  MACHINERY  SUPPORTS 


129 


The  opinion  of  some  authorities  regarding  the  holding 
power  of  expansion  bolts  is  exemplified  by  the  building  laws 
of  some  large  cities — New  York,  for  example.  The  building 
rules  regarding  landings  for  fire  escapes  specify  the  use  of 
through-bolts,  and  especially  forbid  the  use  of  expansion  bolts 
for  holding  such  landings  in  place  against  the  sides  of  buildings. 
While  expansion  bolts  may  and  do  hold,  it  will  not  pay  to  run 
the  risk.  It  is  better  to  put  in  the  reliable  through-bolt  and  secure 
absolute  safety. 

DRILLING  HOLES  IN  CONCRETE. 

Concrete  is  pretty  hard  stuff  to  drill  at  best — provided  it  is 
properly  made — and  the  drills  should  not  be  made  with  too  hard 


FIG.   51.— DRILLING  HOLES   IN  CONCRETE. 

a  cutting  edge  or  they  will  break  badly.    Use  a  rather  soft  drill, 
and  harden  a  little  more  if  necessary  as  the  cutting  proceeds. 


130  MILLWRIGHTING 

Just  as  small  and  as  short  a  drill  should  be  used  as  will  suffice 
to  make  the  hole  large  and  long  enough  for  the  purpose.  For 
the  first  portion  of  a  hole  it  makes  little  difference  what. sort  of 
a  drill  is  used,  as  the  concrete  is  abundantly  able  to  withstand 
the  strain,  but  when  the  hole  is  about  breaking  through  the 
concrete,  then  is  the  time  that  the  small  light  drill  counts 
heavily. 

Fig.  51  illustrates  the  effect  of  drilling  with  heavy  and  with 
light  drills.  The  hole  a  may  be  started  with  a  drill  which  will 
give  a  hole  2  inches  or  more  in  diameter  as  desired,  but  if  no 
precautions  are  taken  the  resulting  hole  will  appear  about  as 
represented  at  c,  the  lower  edge  of  the  concrete  being  broken  or 
flaked  off  sometimes  as  much  as  10  inches  in  diameter.  Although 
this  may  be  repaired,  it  takes  time  for  the  new  concrete  to  harden 
and  it  does  not  make  as  good  looking  a  job  as  where  there  is  a 
clean-cut  hole  right  through  the  concrete,  as  shown  at  /. 

To  obtain  such  holes,  start  them  with  a  full-sized  drill  as  at  a 
and  when  partly  through  the  concrete  change  to  the  small  light 
drill  b  and  work  through  the  rest  of  the  concrete.  A  piece  of 
timber  placed  underneath  where  the  hole  is  to  be  made  and  set 
up  solid  by  means  of  a  jack-screw  or  a  lever,  as  shown  at  d, 
will  prevent  a  .good  deal  of  the  chipping  or  breaking  off  of  the 
concrete,  when  the  drill  breaks  through  the  lower  surface.  If 
a  jack-screw  is  not  at  hand,  use  the  "rocking-horse"  method  of 
leverage,  as  illustrated  at  g,  where  that  timber  is  placed  under- 
neath the  spot  where  the  hole  is  to  come  through  the  concrete. 

"ROCKING-HORSE"    SUBSTITUTE    FOR    JACK-SCREW. 

The  block  h  is  placed  in  position  as  shown,  the  level-timber  k 
put  in  place  and  the  far  end  raised  to  enable  wedge  /  to  be 
inserted  between  the  timber  and  the  block.  The  lever-end  of  the 
timber  k  is  then  depressed  as  far  as  it  will  go,  or  until  it  strikes 
the  ground,  and  wedge  i  is  inserted.  Timber  k  is  again  raised 
and  wedge  /  pushed  or  driven  in  as  far  as  it  will  go,  then  the 
operation  is  repeated  at  wedge  i  again.  After  two  or  three 
turns  at  forcing  each  of  the  wedges,  the  timber  g  will  be  pretty 
snug  against  the  floor  above,  and  the  drilling  may  be  proceeded 
with. 


WALLS  AND  MACHINERY  SUPPORTS          131 

After  the  small  drill  has  been  put  through  the  concrete,  the 
hole  may  be  enlarged  very  readily  with  the  larger  drill  and  with- 
out much  danger  of  spalling  the  under  side  of  the  hole.  It  is 
well,  however,  to  keep  the  supporting  timber  in  place  until  the 
large  drill  has  been  made  to  do  its  work. 

When  drilling  holes  through  walls,  the  same  precautions 
should  be  observed  and  the  smaller  drill  used  unless  there  is  a 
way  of  laying  out  the  hole  accurately  of  both  sides  of  the  wall 
so  that  drilling  may  be  done  partly  through  from  either  side  of 
the  wall.  The  timber  may  be  removed  after  the  small  drill  has 
pierced  the  wall  and  the  larger  drill  used  from  the  opposite  side 
of  the  wall  from  which  the  hole  was  started. 


SHAFT-SUPPORTING  PIERS. 

Piers  for  supporting  a  line  of  shafting,  be  they  brick,  stone, 
concrete  or  wood,  must  be  designed  and  constructed  to  carry  the 
weight  and  other  strains  likely  to  come  upon  the  piers  in  question. 
Given  a  shaft  34  feet  long,  say  3  15/16  inches  in  diameter,  with 
pulleys  scattered  along  the  length  as  required  to  drive  the  several 
machines,  and  it  is  evident  that  some  of  the  piers  must  withstand 
a  severe  pull  while  other  of  the  piers  under  the  same  shaft  have 
little  to  carry  except  the  weight '  of  the  shaft  and  its  load  of 
material.  The  pull  on  some  of  the  piers  is  in  one  direction  or  the 
other  as  the  belts  happen  to  lead  off,  and  it  stands  to  reason 
that  the  piers  need  to  be  designed  to  carry,  or  to  withstand, 
the  various  weights  and  strains  to  which  they  are  severally 
subject. 

It  is  necessary,  therefore,  that  each  pier  be  designed  for  its 
own  particular  work,  and  to  build  all  these  piers  of  the  same 
size  and  weight,  irrespective  of  the  load  and  kind  of  load  which 
each  is  to  carry,  is  very  poor  engineering  and  poor  millwright- 
ing,  too.  Let  Fig.  52  represent  the  plan  of  a  line  of  shafting 
upon  which  the  sizes  of  the  various  pulleys  are  given,  their 
location,  and  the  diameter  of  each  pulley,  together  with  the 
width  of  each  belt.  As  noted,  the  shaft  is  located  six  feet 
above  the  floor  line,  and  it  is  required  to  ascertain  the  size, 
shape  and  construction  of  the  several  piers,  including  one  timber 
trestle,  as  laid  down  upon  the  drawing  in  Fig.  52. 


132 


MILLWRIGHTING 
CALCULATING  THE  BELT  PULL. 


Before  the  necessary  piers  can  be  calculated,  the  belt  strains 
must  all  be  calculated  and  the  weights  of  the  shafts  and  pulleys 
must  be  known  in  order  to  determine  the  dead  and  live  loads 
upon  each  pier  or  foundation.  In  Fig.  52  the  bearings  and,  of 
course,  the  piers  are  designated  as  I,  II,  III,  V  and  VI. 
The  pulleys  are  as  follows:  Engine  pulley  A,  72x21  inches  carry- 
ing a  20-inch  double  leather  belt  from  the  engine.  Pulley  B 
is  46x15  inches  and  stands  up  under  the  pull  of  a  14-inch  Gandy 
belt.  Pulley  C  is  36x13  inches  and  carries  a  12-inch  Gandy 


<D 

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I 

FIG.  52.— SHAFT-SUPPORTING  PIERS. 

belt,  while  pulley  D  is  48x15  inches,  and  is  also  fitted  with  a 
Gandy  belt  14  inches  wide. 

It  is  not  known  how  much  power  is  transmitted  through  the 
several  belts  and  nobody  cares  as  far  as  the  pier  calculations 
are  concerned,  for  the  proper  way  is  to  calculate  the  piers  for 
the  full  power  which  the  belt  can  transmit  without  slipping  on 
the  pulleys.  Here  we  come  to  one  of  the  open  questions  in  mill- 
wrighting,  a  question  which  has  been  discussed  since  the  first 
belt  was  started  and  which  will  be  discussed  until  the  direct 
connected  electric  motor  has  driven  the  last  belt  out  of  busi- 
ness. Every  man  must  work  out  the  problem  for  himself  in  the 
light  of  his  own  environment  and  conditions. 

WORKING  POWER  OF  BELTS. 

The  writer  has,  for  the  past  three  years,  adopted  a  rule  which, 
though  it  may  be  a  trifle  expensive  in  first  cost,  has  proved  very 
economical  in  maintenance  charges  and  which  has  resulted  in 
slipping  belts  being  entirely  unknown  in  every  factory  constructed 
according  to  the  rule  in  question,  which  is : 


WALLS  AND  MACHINERY  SUPPORTS 


133 


"Never  load  a  belt  more  than  40  pounds  pull  to  the  inch  of  its 
width." 

This  rule  is  applied  alike  to  all  belts — leather,  rubber,  Gandy 
or  plain  stitched  cotton,  and  by  the  way,  there  are  so  many 
varieties  of  the  "Original  Gandy"  belt  in  the  market  that  this 
excellent  material  should  always  be  specified  as  "impregnated 
stitched  cotton  belting,"  which  will  permit  the  use  of  any  make 
of  that  kind  of  belt  which  may  pass  the  specifications,  a  discus- 
sion of  which  will  be  found  in  its  proper  place. 

But  belts  are  sometimes  caught,  wound  up  around  the  shafts 
or  on  the  pulleys,  and  broken  in  that  manner;  therefore  it  is 
necessary  that  the  shafting  be  erected  upon  something  solid 


D 


m^mW//W/m^^^ 

FIG.  53.— BELT  PULL  ON  SHAFT-SUPPORTING  PIERS. 


enough  to  withstand  the  breaking  of  any  one  of  the  belts.  It  is 
not  likely  that  all  the  belts  will  catch  and  break  at  the  same 
time,  hence  the  piers  calculated  with  strength  sufficient  to  with- 
stand the  strain  of  the  belt  located  the  nearest  to  that  pier  (the 
strain  when  the  belt  breaks)  will  be  considered  amply  strong  to 
stand  any  strain  likely  to  ever  come  upon  the  pier  in  question. 
The  breaking  strength  of  leather  varies  from  1500  pounds  to 
3000  pounds  tensile  strength.  As  a  belt  is  always  weakened 
somewhat  by  the  joining  together  of  the  several  pieces  com- 
posing it,  2500  pounds  to  the  square  inch  will  be  assumed  to  be 
the  average  breaking  strength  of  leather  belts.  The  thickness 
of  belt  leather  is  about  0.16  inch,  or  there  are  6*4  thicknesses  to 
the  inch,  giving  a  strain  of  2500-^-6.25=400  pounds  pull  to  the 


134  MILLWRIGHTING 

inch  of  belt  width  necessary  to  break  it.  Giving  a  factor  of 
safety  of  10  brings  the  working  capacity  of  the  belt  down  to  40 
pounds,  mentioned  above  as  being  particularly  desirable. 

It  having  been  assumed  that  there  will  not  be  more  than 
400  pounds  to  the  inch  of  width  pull  on  the  belt  at  any  time,  a 
clue  is  given  to  the  strength  of  foundation  necessary  to  with- 
stand the  belt  pull.  Referring  to  Fig.  53,  it  will  be  noted  that 
the  strain  on  pier  VI,  for  instance,  is  brought  to  it  through  two 
folds  of  belt  Dlt  and  D2,  either  of  which  may  be  loaded  to  400 
pounds  to  the  inch  of  width.  But  as  the  shaft  is  running  in 
the  direction  indicated  by  the  arrow,  the  upper  fold  Dlt  must  take 
the  400-pound  strain  when  the  belt  catches  and  breaks;  there- 
fore we  will  neglect  the  pull  on  fold  of  belt  D2,  and  calculate 
only  for  400  pounds  to  the  inch  of  width  on  belt  D^ 

PULL  ON  WORKING  AND  ON  IDLE  FOLDS  OF  A  BELT. 

When  the  belt  on  pulley  D  is  working  it  is  under  a  certain 
strain,  due  to  the  weight  of  the  belt  and  the  tightness  with  which 
the  belt  is  placed  on  the  pulleys.  Be  that  strain  what  it  may, 
the  pulley  D  is  under  no  more  strain  when  it  is  working  than 
when  the  pulley  is  at  rest.  The  40  pounds  working  pull  allowed 
in  any  belt  is  only  the  difference  in  strain  between  sides  D±  and 
ZX  when  the  belt  is  working.  The  total  strain  in  the  belt  upon 
the  pulley  and  the  shaft  is  the  same  whether  the  belt  is  working 
or  is  standing  still.  That  is :  the  strains  in  the  working  and  idle 
folds  of  any  belt  will,  if  added  together,  be  found  to  be  the  same 
whether  the  belt  is  working  to  its  full  capacity  or  is  standing  still. 
But  as  Z>±  is  the  working  fold  of  that  belt,  there  is  more  strain 
upon  the  shaft  when  this  belt  is  working  than  when  it  is  idle, 
for  the  reason  that  the  strain  on  D2  is  diminished  by  the  same 
number  of  pounds  that  Dt  is  increased,  thus  making  14X40=560 
pounds  more  pull  at  b  than  there  is  at  c.  As  the  leverage  of 
point  b  is  4  feet  greater  than  the  leverage  of  point  c,  it  will  be 
noted  that  there  has  been  a  change  in  the  leverage  exerted  to  tip 
over  the  pier. 

But  as  it  has  been  decided  to  calculate  the  pier  to  withstand 
a  force  of  400  pounds  to  each  inch  width  of  belt  exerted  at  a, 
Fig.  53,  to  tip  over  pier  VI,  Fig.  52,  we  need  only  consider  that 
force  of  400X14=5600  pounds  as  exerted  horizontally  at  a, 


WALLS  AND  MACHINERY  SUPPORTS 


135 


6  feet  from  the  surface  of  the  ground.  Should  it  be  necessary 
to  go  to  a  depth  of  4  feet  to  secure  suitable  bearing  soil  for  the 
bottom  of  the  pier,  it  becomes  the  fact  that  the  5600  pounds  is 
exerted  through  a  lever  6-j-4=10  feet.  The  force  applied  at 
the  end  of  any  lever,  multiplied  by  the  length  of  that  lever, 
reduces  the  leverage  to  a  length  of  1  foot,  and  it  is  called  the 
"moment"  of  that  force.  Thus  the  moment  of  the  force  5600 
at  the  end  of  a  12-foot  lever  is  12X5600=67,200.  In  other 
words,  if  the  foundation  were  1  foot  long,  it  must  be  made  to 


5,600 

Tr 

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Floor  Level 


122222 


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LLJL 


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FIG.   54.— CALCULATING  WEIGHT  NECESSARY  IN  A  PIER. 

weigh  67,200  pounds  in  order  to  balance  against  being  tipped 
over  by  the  belt  pull  10  feet  above. 

According  to  the  figures  found  as  above  and  shown  by  Fig. 
54,  the  foundation,  if  made  2  feet  long  from  d  to  /,  would  have 
to  weigh  only  33,600  pounds,  provided  the  weight  could  all  be 
applied  at  point  d,  which  is  impossible  as  the  weight  of  the 
foundation  is  evenly  distributed  all  the  way  to  / — two  feet  dis- 
tant, therefore,  while  the  full  holding-down  power  of  a  pound 
weight  at  d  would  be  realized  in  preventing  the  foundation  from 
tipping  around  the  point  /,  a  pound  weight  at  that  point  (/) 


136  MILLWRIGHTING 

would  have  no  holding-down  power  whatever  as  it  rests  upon 
the  ground  at  the  point  of  turning,  or  the  fulcrum  of  the  levers. 
Therefore  the  full  holding  power  of  a  foundation  2  feet  long 
would  he  only  one-half  the  amount  it  appears  to  have,  and  the  foun- 
dation must  be  2  feet  long  and  weigh  67,200  pounds  instead  of 
33,600  pounds  as  above  noted.  While  the  above  may  not  be 
exactly  true  in  a  scientific  way,  it  is  close  enough  for  our  pur- 
pose of  roughly  calculating  a  shafting  pier.  Thus,  were  the 
pier  made  4  feet  long,  it  need  have  only  a  weight  of  33,600 
pounds  in  order  to  keep  the  belt  pull  at  b  from  tipping  over  pier 
VI  by  rocking  it  upon  one  edge  of  the  foundation.  The  foun- 
dation being  increased  in  length  to  g  becomes  4  feet  in  a  direc- 
tion crosswise  of  the  shaft.  Lengthwise  of  the  shaft  it  makes 
no  difference  how  far  the  pier  extends  as  long  as  the  masonry 
is  strong  enough  so  that  it  does  not  break  apart.  Therefore  the 
pier  foundation  may  be  made  as  wide  as  from  h  to  i  (Fig.  54) 
or  it  may  extend  from  j  to  k  as  may  be  found  necessary  to  give 
the  pier  stability  and  to  secure  a  footing  large  enough  to  suit 
the  carrying  quality  of  the  soil  -upon  which  the  pier  is  to  erected. 
The  weight  of  the  material  ranges  from  about  140  pounds  to 
the  cubic  foot  for  brick  masonry  to  150  or  160  pounds  for  con- 
crete. Taking  the  figure  for  brick,  140  pounds  to  the  cubic  foot, 
it  will  require  33,660-^-140=240  cubic  feet  of  masonry,  not  count- 
ing the  weight  of  the  shaft  which  is  somewhere  near  as  follows : 

7-foot  shaft,  3  15/16  inches    288  pounds. 

13  15/16-inch  pillow-block   100 

4  bolts   25 

1  pulley,  48x15  inches 550 

30  feet  of  14-inch  x  6-ply  impregnated  s.c. 

belt 140          " 

Total  weight   1103  pounds. 

The  effect  of  subtracting  1103  pounds  from  the  total  necessary 
load  of  33,600  pounds  leaves  23,497  pounds  of  masonry  neces- 
sary, amounting  to  about  231  cubic  feet.  As  the  pier  is  to  be 
10  feet  high,  it  is  obvious  that  the  cross-sectional  area  must  be 
231-f-10=23.1  (slide  rule  calculations)  and  if  the  pier  is  to  be  made 
4  feet  long  its  width  must  be  about  5  feet  10  inches,  or  wider 
than  it  is  long. 

It  is  obvious  that  the  above  noted  dimensions  are  not  very 


WALLS  AND  MACHINERY  SUPPORTS 


137 


suitable  for  the  pier  in  question  and  that  the  length  should  be 
increased  while  the  width  is  diminished.  Should  the  length  be 
increased  to  8  feet  the  turning  resistance  is  doubled,  and  there  is 
necessary  only  16,800  in  load  instead  of  33,600.  But  the  Shaft 
and  pulley  weight  must  be  deducted  from  the  above,  leaving 
16,800—1103=15,697  pounds  of  masonry  required.  At  140 
pounds  to  the  foot,  this  requires  about  112  cubic  feet.  Should  the 
length  of  pier  be  made  8  feet  at  the  bottom  and  4  feet  at  the  top, 
then  there  would  be  an  average  of  6  feet  in  length,  a  surface  of 
60  square  feet  area.  As  the  cubic  contents  of  the  pier  must  be 
112  feet,  the  width  is  found  to  be  112^60,  or  almost  2  feet 


FIG.   55.— ECONOMY   OF   MATERIAL   BY  USING  REINFORCED  CONCRETE. 

(1  foot,  I0y2  inches  nearly)  and  the  pier  should  be  made  2  feet 
wide.  There  is  nearly  3y2  cubic  yards  of  masonry  in  the  pier, 
and  this  would  cost  in  brick  from  $10  to  $20  a  yard.  If  built  of 
concrete,  the  pier  would  cost  from  $4  to  $10  a  cubic  yard. 

The  area  of  the  pier  on  the  bottom  is  8X2=16  square  feet, 
and  as  the  load  is  only  a  little  more  than  8  tons  it  will  be  seen 
that  the  load  is  only  about  one-half  a  ton  to  the  square  foot,  so 
that  the  pier  would  be  safe  in  almost  any  kind  of  soil  without  any 
extension  whatever  in  the  shape  of  a  footing.  The  outline  of 
the  pier,  both  side  and  end  elevation,  is  shown  by  the  dotted 
lines  in  Fig.  54. 

Should  it  be  found  necessary  to  economize  in  material,  the 
millwright  may  construct  a  pier  as  shown  by  Fig.  55,  where  the 


138  MILLWRIGI1TING 

quantity  of  masonry  is  reduced  from  112  to  6  cubic  feet.  In 
this  form  of  construction,  the  bearing  for  the  67,200-pound 
thrust  moment  12  inches  above  the  bottom  of  the  foundation  is 
carried  10  feet  away  toward  b,  and  instead  of  having  been  able 
to  divide  the  thrust  moment  by  4,  as  in  Fig.  54,  we  are  now  able 
to  divide  it  directly  by  10,  the  footing  at  b  and  intermediate 
between  b  and  c  being  sufficient  to  absorb  the  pressure. 

The  division  by  10  allows  the  belt  pull  to  be  balanced  by  a 
masonry  load  of  6720  pounds,  and  deducting  the  shaft-load  of 
1103  pounds  there  remains  only  5617  pounds  weight  of  masonry 
necessary,  or  a  trifle  more  than  40  cubic  feet  for  the  pillar  g,  e. 
Dividing  40  by  10  gives  4  square  feet  as  the  cross-section  area 
of  the  pillar  (it  can  hardly  be  called  a  pier  now),  which  would 
correspond  to  its  being  4  feet  long  and  12  inches  thick  or  wide. 
This  does  not  take  into  account  the  brace  which  is  run  off  toward 
b,  more  than  one-half  of  which,  in  weight,  is  accountable  as  being 
attached  to  g,  c,  thereby  increasing  the  resistance  of  the  pier  to  a 
great  extent  which  has  been  made  no  account  of  whatever  in 
the  calculations,  but  which  would  decrease  materially  the  number 
of  cubic  feet  of  masonry  necessary  in  the  pillar  g,  c.  There  is 
also  the  holding  po\ver  of  the  soil  on  top  of  b,  h,  which  is  con- 
siderable and  may  be  taken  into  account  if  necessary;  but  this 
pier  is  already  as  small  as  could  be  safely  constructed,  and  the 
soil  load  is  neglected.  To  give  the  necessary  strength  of  pier 
to  enable  it  to  withstand  the  transverse  (breaking)  strain  of  the 
belt  pull,  some  steel  reinforcing  bars  are  put  in  as  shown  at 
a,  a,  a,  a.  The  strength  of  steel  necessary  at  any  point  between  b 
and  c  may  be  found  by  considering  its  distance  from  c  as  the 
length  of  a  lever  which  is  to  be  divided  into  the  moment — 67,200. 
Thus  at  a  point  6  feet  from  c,  toward  b,  the  load  will  be 
67,200-1-6=11,200  pounds,  which  may  be  considered  at  transverse 
strain  tending  to  break  the  brace  foundation  at  a  point  6  feet 
from  c. 

CALCULATING  THE   STEEL  REINFORCING. 

Should  the  transverse  strain  be  divided  by  the  thickness  of  the 
footing  at  the  point  of  load,  it  will  be  very  close  to  the  tensile 
strain  tending  to  pull  in  two  the  lower  side  of  the  foundation; 
therefore  it  is  safe  to  provide  reinforcing  capable  of  carrying  a 


WALLS  AND  MACHINERY  SUPPORTS          139 

tensile  strain  of  11,200  pounds.  Should  it  be  determined  to  use 
Ransome  bars,  their  size  and  number  may  be  calculated  from  the 
data  given  on  page  88,  chapter  VII ;  but  if  ordinary  round  steel 
is  to  be  used,  it  is  safe  to  use  the  boiler  inspector's  rule  for  braces 
and  allow  5000  pounds  pull  on  each  round  brace  1  inch  in  diame- 
ter. This  amounts  to  nearly  6350  pounds  to  the  square  inch 
of  section,  a  factor  of  safety  of  about  10. 

Thus  there  will  be  required  11,200-^5,000=2.2  rods  1  inch 
in  diameter.  As  it  was  found  on  page  119  that  one  rod  1  inch  in 
diameter  was  equal  to  four  %-inch  rods,  it  may  be  considered 
safe  to  place  nine  ^-inch  rods  in  the  footing  as  shown  at  i,  i. 
According  to  calculation,  more  rods  would  be  required  nearer  to 
c  but  for  the  bracing  h,  which  is  run  up  as  shown  for  the  pur- 
pose of  increasing  the  depth  leverage  of  the  footing,  thereby 
making  the  tension  less  in  the  reinforcing  rods. 

The  amount  of  steel  necessary  in  the  pillar  is  to  be  calculated 
in  the  same  manner — thus  at  a  point  midway  between  shaft  and 
bottom  of  pier,  the  strain  will  be  67,000-^5=11,200,  as  before, 
but  as  the  pillar  is  4  feet  long  at  that  point,  the  strain  upon  the 
reinforcing  is  reduced  to  11,200-^4=2800  pounds.  When  calcu- 
lating the  foot  brace,  it  was  ascertained  that  a  round  steel  rod 
1/2  inch  in  diameter  would  safely  carry  1250  pounds,  and  as 
2800-f-1250=2.22,  we  may  safely  say  that  three  %-inch  rods  will 
carry  the  strain  in  the  pillar,  provided  the  bracing  masonry  at  h 
be  made  of  a  length  from  the  reinforcing,  that  the  tensile  strain 
at  any  vertical  distance  from  the  bottom  of  the  pier,  divided  by 
the  length  of  cross  section  at  that  point,  shall  not  exceed  3750. 
Thus  the  rule  for  the  slope  or  batter  at  h  is  found,  and  it  will  be 
ascertained  by  calculating  several  points  in  the  slope  on  that 
side  of  the  pier  that  the  line  b  h  f  g •  is  a  portion  of  a  hyperbola, 
and  the  experienced  calculator  of  this  class  of  work  will  at  once 
lay  down  such  a  curve  and  he  will  determine  it  in  much  the 
same  manner  that  the  expansion  line  is  determined  for  an  indi- 
cator card  from  the  steam  engine.  It  is  the  same  curve  in  both 
instances. 


CHAPTER  IX. 

ROOF  TIMBERING  AND  TRUSSES. 

When  a  roof  is  to  be  supported  upon  walls  and  posts  a-plenty, 
the  problem  is  a  very  simple  one — merely  that  of  ascertaining  the 
strength  of  timbers  necessary  to  support  the  roofing  and  whatever 
load  of  snow  may  collect  upon  it  together  with  the  usual  amount 
allowed  for  wind  pressure,  which  should  be  taken  at  about  40 
pounds  to  the  square  foot  for  the  highest  winds  likely  to  be 
encountered  by  a  surface  standing  squarely  across  the  direction  in 
which  the  wind  is  blowing.  It  is,  then,  necessary  to  brace  the 
walls  of  a  building  to  withstand  a  wind  pressure  of  40  pounds 
to  the  square  foot. 

The  roof  should  be  figured  to  withstand  the  same  pressure, 
but  as  the  surface  of  the  roof  is  not  at  right  angles  to  the  wind, 
but  slopes  to  a  considerable  angle,  it  will  be  about  right  to 
multiply  by  40  the  sine  of  the  angle  made  by  the  roof  with  the 
horizon.  This  means  that  a  roof,  no  matter  how  wide,  which 
rises  one  foot,  will  be  taken  as  exposing  one  foot  of  resisting  sur- 
face to  the  wind,  instead  of  its  whole  width.  In  the  instance 
mentioned,  the  vertical  hight  of  the  roof  would  be  multiplied  by 
the  length  of  course.  This  means  that  the  length  of  a  roof,  mul- 
tiplied by  its  vertical  hight  and  by  40,  will  give  the  wind  load 
which  the  roof  should  be  constructed  to  resist. 

Trautwine  lumps  the  snow  and  wind  loads  at  20  pounds  to  the 
square  foot  of  roof,  12  pounds  for  snow  and  8  pounds  for  wind 
pressure.  The  snow  load  is  for  north  of  the  35th  degree  of  lati- 
tude, and  the  load  must  be  estimated  more  or  less  according  to 
the  characteristics  of  the  locality.  For  instance,  at  Albany,  N.  Y., 
there  is  comparatively  little  snow,  only  two  or  three  feet  is 
usually  in  evidence  at  any  time ;  while  just  over  the  mountains, 
in  western  Massachusetts,  the  snow  piles  up  eight  feet  deep 
nearly  every  winter.  Thus  locality  must  largely  determine  the 
snow  and  wind  factor  required  in  any  roof  construction. 

140 


ROOF  TIMBERING  AND  TRUSSES  141 

WEIGHT  OF  ROOF  COVERING. 

The  weights  of  ordinary  roofs  may  be  taken  about  as  follows : 

Corrugated  iron 2  to     3  Ibs.  sq.  ft. 

Slate : 7  to     9 

Shingles  on  strapping 2  to     3 

If  on  boards,  add 3 

If  plastered  below   rafters,  add....  6 

Tin   (not  counting  boards) 1 

Matched  sheathing    3  to     5 

Tiles  12  to  25 

Rafters    1.5  to    3 

Purlins,  steel   2  to     4 

Purlins,  wood 2  to     4 

Steel  shingles 1  to     3 

Roof  truss,  steel — multiply  distance  between  supports 
by  distance  between  trusses  and  multiply  product  by  the 
length  of  truss  divided  by  25,  with  1  added  to  the  quo- 
tient. The  weight  of  a  wooden  truss  is  a  little  less.  By 

algebra,  W^al^gH-l) ;  where 

W=weight  of  truss 
a— distance   between   adjacent   trusses 
l=length  of  truss  between  supports. 

ROOF  TRUSSES. 

As  stated,  where  there  are  plenty  of  posts,  purlins  may  be  run 
to  carry  the  roof  timbers  or  rafters  and  no  framing  will  be 
required,  but  where  a  clear  story  is  required,  and  the  distance 
between  walls  is  too  great  to  be  covered  by  a  single  span,  then 
some  form  of  truss  is  necessary  to  sustain  the  roof  and  its  water- 
proofing. While  it  is  not  the  purpose  of  this  book  to  go  deeply 
into  truss  designs  and  construction,  a  few  first  principles  are  given 
to  enable  the  millwright  to  plan  a  simple  roof  or  truss. 

The  common  pitch  roof  with  its  rafters,  collar  beams,  plates 
and  tie-beams  is  nothing  more  or  less  than  a  simple  trussed  roof, 
and  the  principles  used  in  determining  the  necessary  strength 
of  rafters  for  such  a  roof  are  the  same  as  are  used  in  calculating 
the  most  complicated  roof  truss.  Fig.  56  shows  a  simple  rafter 
roof,  the  width  of  building  /  being  the  distance  between  supports 
of  the  truss,  and  the  distance  between  rafters  a  being  the  distance 
between  trusses.  This  will  be  taken  as  2  feet  and  /  may  be  taken 
as  20  feet. 


142 


MILLWRIGHTING 


Next,  to  calculate  the  weight  of  the  roof  which  is  to  be  slate 
on  sheathing:  The  roof  is  what  is  known  as  "half-pitch,''  the 
hight  of  ridge  being  one-half  width  of  building.  This  brings 
the  length  of  rafter  from  plate  to  ridge  about  14.1  feet,  and  count- 
ing the  projection  of  the  eaves  the  roof  slant  will  be  about  16 
feet.  From  the  list  of  weights  of  roof  materials  it  is  found  that 
the  weight  of  the  rafters  will  be  about  2  pounds  to  the  foot, 
sheathing  4  pounds,  tin  1  pound;  a  total  of  7  pounds.  To  this 
should  be  added  about  1  pound  for  the  collar-beams  b,  making 
the  total  roof  weight  8  pounds  to  the  square  foot.  A  space  14x2 
feet  is  handled  by  each  rafter,  therefore  the  load  carried  by  each 
pair  of  rafters  will  be  8X28X2=448  pounds. 


1 

,, 

j 

,-H 

.  i  . 

FIG.  56.— CALCULATING  STRENGTH  OF  RAFTERS. 

Add  to  the  above  a  load  of  20  pounds  to  the  foot  for  wind 
and  snow  loads  and  it  will  be  found  that  each  rafter  has  to  carry 
a  total  of  560  pounds  or  1160  pounds  for  the  pair  of  rafters, 
and  the  strength  necessary  can  be  figured  taking  the  rafter  as  a 
beam  7  feet  long  (from  c  to  g)  fixed  at  both  ends,  carrying  an 
evenly  distributed  load  of  280  pounds  and  inclined  at  an  angle 
of  45  degrees.  The  section  of  rafter  from  g  to  c  must  carry 
the  same  amount  of  load,  also,  in  addition  to  the  280  pounds  of 
evenly  distributed  load  from  e  to  g.  there  is  a  load  of  280  pounds 
more  at  point  g,  owing  to  the  tying  together  of  the  rafters  by  the 
collar-beam  b. 

A  SIMPLE  ROOF  TRUSS. 

Should  it  become  necessary  to  put  a  heavier  roof  on  the  struc- 
ture, you  can  use  2-inch  planking  so  as  to  permit  the  rafters  to  be 


ROOF  TIMBERING  AND  TRUSSES 


143 


replaced  by  crude  trusses  placed  farther  apart  than  the  rafters, 
and  forming  a  sort  of  nailed-up  truss,  as  shown  by  Fig.  57.  The 
calculations  for  the  weight  of  roof  will  be  slightly  different  when 
this  form  is  used.  First,  the  weight  of  the  truss  to  the  square 
foot  of  roof  must  be  found,  instead  of  taking  a  lump  sum  for 
the  weight  of  the  rafters.  Taking  the  formula: 


the  known  vaiues  are  put  in  place  of  the  letters  and  there  is 
obtained  : 

90 

W=3X20X(-^H-1),  or 
£Q 

W=60X  1-8=108  pounds. 


FIG.    57.— A   SIMPLE    ROOF    TRUSS. 

Really  the  above  rule  says  that  the  weight  of  a  truss  (steel) 
for  a  20-foot  span  will  be  1.8  pounds  to  the  square  foot.  When 
the  truss  is  made  of  wood,  as  in  this  instance,  it  is  probably  about 
100  pounds  in  weight  or  possibly  1.6  pounds  weight  to  the 
square  foot.  The  great  loss,  however,  lies  in  the  extra  thickness 
of  planking  required  with  trusses  spaced  further  apart  than  the 
rafters. 

The  weight  of  the  planking  would  be  about  8  pounds  to  the 
foot,  truss  2  pounds  as  before,  and  tin  1  pound,  making  a  total 
of  11  pounds.  And  11X14X3=462,  or  924  pounds  to  be  car- 
ried by  each  truss.  Add  to  this  20X14  X3=840  pounds  for  wind 
and  snow.  This  amount  added  to  the  weight  of  roof  makes 
840+462X2=2604  pounds  to  be  carried  by  each  truss,  or  1300 


144 


MILLWRIGHTING 


pounds  at  each  end,  d  and  c.  To  ascertain  the  strains  in  each 
member  of  this  truss,  the  millwright  may  make  the  diagram 
Fig.  58  and  there  lay  out  the  several  strains  as  they  are 
determined. 

Were  the  stresses  at  each  joint  to  be  computed  for  the  total 
roof  load  distributed  among  the  joints  1,  2,  3,  4,  and  5,  in  such 
a  manner  that  1  and  5  receive  one-half  as  much  as  each  of  2,  3, 
and  4,  the  loads  on  which  are  equal,  then  1  and  2  would  each 
receive  %  of  2600=325  pounds,  while  2,  3,  and  4  would  each 
carry  14  of  2600=650  pounds.  But  as  the  wind  pressure  is 
never  carried  by  both  sides  of  the  roof  at  the  same  time,  there 
must  be  some  other  method  of  distributing  the  loads,  and  this 


D5U 

115.5 »  (115.5 

125.5V  325  1 325  \  125.5 
84.    f        I        I   84. 


FIG.   58.— WEIGHT,   SNOW  AND  WIND   STRESSES  AT  JOINTS  OF  TRUSS. 

had  better  be  done  by  calculating  separately  the  loads  caused  by 
the  weight  of  the  material  in  truss  and  roof,  the  snow  load,  and 
the  wind  load,  and  the  three  sets  of  figures  at  each  joint  of  the 
truss  refer  respectively  to  loads  for  weight  of  material,  snow  and 
wind,  as  follows : 

Weight  of  material  in  roof 924  pounds. 

"    snow   load    1004 

"    wind  pressure    672 

Dividing  each  of  these  quantities  by  8  for  the  loads  at  1  and 
5,  and  by  4  for  the  loads  at  2,  3,  and  4,  the  material  and  the 
snow  loads  are  found  to  be  as  follow : 


924-^8=115.5 
1004-^8=125.5 


924-^4=231 
1004-^4=251 


ROOF  TIMBERING  AND  TRUSSES 


145 


But  the  wind  load  of  672  pounds  must  all  be  carried  by  the 
truss  on  one  side  of  the  roof,  hence  one-half  of  this  load  comes 
upon  the  truss  joint  2  while  the  rest  is  evenly  divided  between 
joints  1  and  3  except  84  pounds  at  (3),  which  is  carried  by 
(5).  This  gives  336  pounds  for  (2),  168  pounds  for  (1)  and 
84  pounds  for  joint  (3),  giving  the  loads  at  the  five  joints  as 
follows : 

No.  1=409 

No.  2=818 

No.  3=650 

No.  4=482 

No.  5=241 

Total,  2600 

Thus  it  will  be  seen  that  the  windward  side  of  the  truss  is 
loaded  the  most  and  that  the  middle  joint  (2),  has  the  most 
load  to  carry  of  any  of  the  joints.  To  take  care  of  the  strain 
upon  the  other  side  of  the  roof  when  the  wind  is  in  the  opposite 
directions,  it  will  be  necessary  to  timber  both  sides  of  the  roof 
according  to  the  wind  pressure  figures  given  for  joints  1  and  2, 
therefore  joints  4  and  5  must  be  calculated  as  though  loaded 
like  joints  1  and  2. 

STRAINS  MODIFIED  BY  WIND  PRESSURE. 

To  properly  take  care  of  the  wind  pressure  strains,  the  sev- 
eral stresses  are  modified  as  shown  by  Fig.  59  and  the  strength 


FIG.  59.— STRESSES  ADJUSTED  TO  WIND  PRESSURE. 

of  the  several  members  of  the  truss  are  arranged  to  meet  the 
strain  as  thus  distributed.  To  find  what  strains  are  present  in, 
or  must  be  met  by  each  strut  or  tie  is  called  "analyzing  the 


146 


MILLWRIGHTING 


truss."  It  is  evident  that  the  several  pushes  and  pulls  in  any 
joint  of  a  truss  neutralize  or  balance  each  other,  and  in  Fig.  59 
it  is  evident  from  an  inspection  of  the  truss  that  members  16 
(1  and  6),  65,  and  63  are  in  tension  and  that  all  the  others  are 
in  compression.  This  being  the  case,  the  first  set  of  members 
can  be  made  in  the  form  of  rods,  if  necessary. 

ANALYZING  THE  STRAINS  IN  A  TRUSS. 

To  properly  understand  the  graphic  method  of  analyzing  a 
truss  by  the  "joint"  method,  something  must  be  known  regard- 
ing the  parallelogram  of  forces,  and  that  subject  must  be  looked 
up  by  the  millwright.  The  other  method  of  ascertaining  the 
strains  in  a  truss  is  by  what  is  known  as  the  section  method,  and 
to  use  that  way  a  section  is  supposed  to  be  cut  through  various 
sections  of  the  truss,  as  at  a,  b,  Fig.  59,  and  the  strains  there 
found  are  studied. 

THE  PARALLELOGRAM  OF  FORCES. 

To  easily  and  quickly  obtain  a  little  knowledge  of  the  parallel- 
ogram of  forces,  procure  some  strong  cord  and  three  spring 
balances.  Hang  up  the  three  balances  with  two  of  them  side 
by  side,  as  shown  by  Fig.  60,  putting  a  little  spreader  between 


FIG.    60.— STUDYING   FORCES. 


FIG.    61.— COMPONENT   AND 
RESULTANT    FORCES. 


the  cords  at  e  that  the  balances  may  hang  perfectly  parallel. 
Then  hang  on  the  third  balance,  and  lastly  put  on  a  weight  d, 
supposedly,  in  this  case,  of  25  pounds.  Any  weight  may  be  used 


ROOF  TIMBERING  AND  TRUSSES  147 

which  is  not  too  great  for  the  small  scales  which  have  a  limit 
of  about  50  pounds  each. 

With  the  balances  adjusted  as  above,  note  the  reading  on 
scale  c,  and  also  note  that  the  reading  on  each  scale  a  and  b  is 
just  one-half  the  reading  of  c.  Next,  separate  the  points 
to  which  scales  or  balances  a  and  b  are  attached  until  they  are 
exactly  twice  as  far  apart  as  the  point  e  is  distant  from  g.  It 
may  require  a  little  juggling  to  obtain  the  desired  positions, 
but  it  can  be  done  by  taking  in  and  letting  out  the  cords  until  the 
desired  arrangement  is  effected.  When  the  cords  have  been 
adjusted,  the  arrangement  will  be  as  shown  by  Fig.  61,  and  it  will 
be  found  that  the  reading  of  scales  a  and  b  is  exactly  equal,  as 
before,  but  they  both  now  indicate  more  than  one-half  the  weight 
of  d,  as  shown  by  balance  c. 

If  it  happens  that  the  balances  have  been  suspended  so  that 
the  distance  /  h  is  exactly  twice  the  distance  e  g  and  if  the  cords 
/  e  and  e  h  are  also  exactly  equal  in  length,  then  the  two  cords 
in  question  will  hang  at  angles  of  45  degrees  with  line  /  h,  and 
the  balances  a  and  b  will  indicate  17.67  pounds  each.  If,  how- 
ever, the  cords  /  e  and  e  h  do  not  chance  to  be  exactly  equal  in 
length,  then  there  will  be  a  slightly  different  reading  on  the 
balances  a  and  b,  and  by  means  of  these  readings  it  is  easily 
possible  to  determine  the  angles  at  which  the  cords  happen  to 
hang. 

In  this  engraving  the  forces  indicated  on  balances  a  and  b 
are  said  to  be  the  component  forces  of  the  force  c,  while  force  c 
is  known  as  the  resultant  of  forces  a  and  b.  As  all  three  of  these 
forces  act  upon  the  same  point  (e)  they  are  said  to  be  concurrent 
forces,  and  Fig.  62  shows  how  such  forces  may  be  measured 
when  they  occur  in  a  truss. 

GRAPHIC  REPRESENTATION  OF  FORCES. 

To  lay  down  upon  a  surface  a  representation  of  the  forces 
acting  at  the  point  e,  Fig.  61,  it  is  necessary  to  use  some  con- 
venient scale  and  let  equal  distances  equal  equal  forces.  Thus 
in  Fig.  62  it  will  be  understood  that  16  pounds  are  represented 
by  a  line  one  inch  long,  and  the  direction  of  that  line  and  the 
arrow  upon  it  indicate  the  direction  in  which  the  force  is  acting. 
If  we  draw  this  line  from  e  to  g,  using  the  scale  of  16  pounds 


148 


MILLWRIGHTING 


to  the  inch,  for  the  reason  that  a  scale  of  sixteenths  can  always 
be  found,  that  line  e  g,  will  represent  a  force  of  25  pounds  acting 
vertically  downward.  The  lines  c  f  and  e  h  are  drawn  at  the 
same  angle  as  in  Fig.  61.  Then  from  the  top  of  the  25-pound 
line,  at  g,  draw  the  line  g  j,  making  it  exactly  parallel  with  line  e  f. 
From  point  /,  where  the  line  g  j  cuts  line  e  h,  measure  to  e, 
and  that  distance  will  be  found  to  be  exactly  17.67  by  the  scale 
shown  at  the  top  of  the  engraving.  This  layout  is  called  the 


FIG.    62.— THE    PARALLELOGRAM    OF   FORCES. 

parallelogram  of  forces,  and  all  truss  calculations  depend  upon 
it  for  their  solution.  It  will  be  noted  that  the  truss,  Fig.  58,  is 
almost  an  exact  representation  of  the  parallelogram  of  forces 
in  an  inverted  position.  That  happens  to  be  a  mere  coincidence, 
but  it  goes  to  show  the  connection  between  the  figures  in  question. 
Having  given  some  of  the  forces  and  their  directions  in  the 
truss,  Fig.  58,  it  is  our  task  to  find  the  rest  of  the  forces  and  their 
directions  in  order  that  the  proper  amount  of  material  may  be  put 
into  those  members  to  enable  them  to  safely  do  their  work. 

"CLOCKWISE"  AND  "COUNTER-CLOCKWISE." 

We  may  begin  at  any  point  in  the  truss  to  analyze  the 
strains,  and  the  usual  custom  is  to  proceed  from  one  joint  to 
another,  always  moving  in  the  same  direction,  until  all  the  joints 
have  been  studied.  There  are  two  directions  in  which  it  is  usual 
to  pass  around  each  joint,  one,  proceeding  from  left  to  right, 
and  called  "clockwise,"  and  the  other  method  of  procedure  is  from 


ROOF  TIMBERING  AND  TRUSSES 


149 


right  to  left,  and  is  called  "counter-clockwise."     It  is  usual  to 
proceed  "clockwise,"  and  that  method  will  be  followed. 

Beginning  at  (1),  Fig.  58,  an  angle  is  found,  one  line  being 
horizontal,  the  other  approaching  the  point  (1)  at  an  angle  of  45 
degrees.  Draw  this  intersection  at  Fig.  63,  and  the  problem 


1636 


FIG.    63.— FORCES    ACTING   AT   POINT    (1). 

becomes  that  of  determining  the  forces  acting  in  the  two  unknown 
elements  (1)  a  and  (1)  b,  whose  directions  are  known,  but  not 
their  force.  To  ascertain  the  magnitude  of  forces  a (1)  and  fr(l), 
Fig.  63,  draw  the  vertical  line  c(l),  Fig.  64,  giving  it  a  length 
of  16.36  sixteenths  of  an  inch;  then  lay  off  line  d  c,  and  as  the 


FIG.   64.— MEASURING  THE  FORCES  ACTING  AT  POINT   (1). 


angle  of  line  d(l)  is  45  degrees,  the  length  of  lines  d  c  and  c(l) 
must  be  equal,  therefore  line  c  d  is  also  laid  off  16.36  sixteenths 
inch  long.  It  now  remains  to  close  the  polygon  of  forces  by 
connecting  d  and  (1)  by  the  line  d(l),  which  when  scaled  is 
found  to  measure  23.50  sixteenths  of  an  inch,  and  it  is  so 
marked  in  the  diagram. 


150 


MILLWRIGHTING 


Having  found  the  amounts  of  the  pressures  and  pulls  upon 
point  (1),  it  is  next  in  order  to  designate  those  strains  by  arrow 
heads  showing  the  direction  in  which  they  act.  As  the  stress  in 
line  c(l)  is  known  to  act  upward,  the  arrow  is  placed  thus  and 
close  to  point  (1)  to  which  it  belongs.  As  the  arrows  in  any 
strain  polygon  must  all  point  in  the  same  direction,  the  direction 
of  the  arrows  in  the  other  sides  are  easily  determined  and  are 
placed  as  shown  in  Fig.  64. 

The  arrows  pointing  to  the  joint  show  compression.  Those 
pointing  away  from  a  joint  indicate  tension.  The  several  joints 
of  the  truss  being  treated  in  a  similar  manner,  the  strains  in  all 
the  members  may  eventually  be  determined.  When  the  arrow 
heads  are  placed  about  each  joint,  it  will  be  found  that  in  some 
members  of  the  truss  there  are  arrow  points  facing  toward  each 
other,  and  in  other  lines  the  arrows  point  away  from  each  other. 
The  rule  which  applies  here  is  that : 

"In  lines  where  arrows  face  each  other,  member  is  in  ten- 
sion." 

''In  lines  where  arrows  leave  each  other,  member  is  in  com- 
pression." 

A  STRESS  DIAGRAM. 

But  there  is  a  much  shorter  method  than  drawing  strain  dia- 
grams of  each  joint  separately.  It  is  usual  to  make  what  is  called 


FIG.  65.— NOTATION  FOR  GRAPHICAL  TRUSS  ANALYSIS. 

a  stress  diagram  of  the  truss  from  which  the  tension  or  com- 
pression of  each  member  may  be  taken  off  at  will.  Such  a  stress 
diagram  of  truss  Fig.  57  is  shown  by  Fig.  65.  The  lettering  of 


ROOF  TIMBERING  AND  TRUSSES  151 

the  lines  is  changed  to  a  lettering  of  the  spaces,  placing  a  letter 
in  each  triangle,  both  inside  and  outside  of  the  truss  diagram. 
By  this  method  the  line  from  (1)  to  (2)  will  be  known  as  a  d, 
and  so  on  through  the  entire  number  of  lines  in  one-half  of  the 
diagram.  As  the  lines  and  their  stresses  are  exactly  the  same 
on  one  end  of  the  diagram  as  on  the  other,  hence  the  same  let- 
ters may  be  used,  as  shown,  with  superior  or  inferior  figures, 
to  designate  the  elements  of  the  remaining  portion  of  the  truss. 
As  the  stresses  are  the  same  in  both  ends,  it  is  only  necessary  to 
calculate  the  strains  for  one  end  of  the  truss. 

In  subsequent  naming  of  stresses,  the  signs  +  and  —  will 
be  used  for  tensile  and  compression  strains  respectively.  Thus, 
referring  to  Fig.  64,  the  strains  there  found  are  +1636  and 
— 2350,  respectively. 

To  construct  a  single  stress  diagram  from  which  all  the  strains 
for  all  the  members  of  the  truss  may  be  taken,  it  is  only  necessary 
to  determine  the  loads  and  the  reactions,  as  shown  by  Fig.  65, 
where  the  loads  are  409,  818,  818,  818  and  409  pounds.  The  reac- 
tions are  1636  and  1636.  It  will  be  noted  that  the  sum  of  the  loads 
and  the  sum  of  the  reactions  are  exactly  equal,  as  should  always 
be  the  case.  To  lay  out  the  stress  diagram  shown  by  Fig.  66, 
commence  at  any  portion  of  the  truss,  preferably  at  (1),  Fig.  65, 
and  lay  down  the  load  there  given,  409,  on  the  vertical  line  of  the 
stress  diagram,  Fig.  66.  Take  any  convenient  scale,  the  larger 
the  better,  and  lay  off  409  to  a  point  which  will  be  called  B.  Next 
lay  off  on  the  line  the  load  818,  and  call  the  end  of  that  distance  E. 
Proceed  in  the  same  manner  with  all  the  loads,  giving  the  end  of 
the  line  representing  each  load  the  capital  letter  which  coincides 
with  the  lower-case  letter  of  the  side  adjacent  to  the  load  in 
question.  Thus  the  load  at  (3)  is  given  the  letter  E.  In  Fig.  65, 
that  load  is  to  be  found  between  letters  e  and  elt  also  between  b 
and  e^.  In  Fig.  66,  the  corresponding  distance  is  to  be  found  at  E, 
between  B  and  Elf 

Having  laid  down  lines  representing  all  the  loads,  ending 
at  (5),  turn  about  that  point  and  lay  off  the  reactions  in  lines  to 
scale  representing  their  value.  Thus  the  lines  representing  1636 
will,  if  the  drawing  is  accurately  made,  just  reach  from  (5)  to  A, 
and  from  A  to  (1),  or  the  ''polygon  closes"  and  the  work  is  right 
so  far.  Then,  from  the  point  B,  which  represents  the  load  line 


152 


MILLWRIGHTING 


of  (1),  Fig.  65,  lay  off  a  line  upon  the  same  angle  as  the  line  b  c, 
and  the  point  where  this  line  intersects  with  the  center  line  drawn 
horizontally  through  A,  Fig.  66,  is  to  be  marked  C,  and  the  length 
of  the  line  C  B  in  the  stress  diagram,  Fig.  66,  represents  the 
amount  of  strain  present  in  the  member  b  c  of  the  truss.  Measur- 
ing the  distance  B  C  demonstrates  that  strain  to  be  1756 
pounds. 

In  a  similar  manner,  the  line  e  d  is  started  at  E  and  laid  down 
on  its  proper  angle  until  it  meets  the  line  drawn  from  C,  parallel 


FIG.    66.— CONSTRUCTING   A   STRESS   DIAGRAM. 


with  c  d,  and  the  point  of  intersection  of  these  lines  is  marked 
at  D.  The  reference  to  letters  on  drawings  No.  65  and  No.  66 
will  readily  be  understood  without  further  mention  of  their  num- 
bers, as  the  capitals  and  lower-case  prevent  any  confusion  be- 
tween them.  The  length  of  lines  D  E  is  the  measure  of  the  stress 
in  member  d  e,  and,  likewise,  the  line  C  D  when  scaled  gives  the 
amount  of  stress  in  c  d.  These  two  quantities  are  found  to  be 
1178  and  578,  respectively. 

Should  a  line  be  drawn  from  E,  parallel  with  line  d±  el}  the 


ROOF  TIMBERING  AND  TRUSSES  153 

measure  of  that  line,  which  is  shown  dotted  from  D±  to  E1}  will 
prove  to  be  the  measure  of  member  d^  elt  and  it  scales  1178  the 
same  as  line  D  E.  Should  points  D  and  D±  be  connected,  the  line 
thus  obtained  measures  818,  and  represents  the  strain  in  line  d  d±. 
The  line  C  A,  1227  long,  is  the  measure  of  the  load  in  a  c,  also 
in  at  cit  thus  giving  all  that  is  necessary  to  make  up  a  stress  rec- 
ord of  the  truss.  The  manner  of  the  load,  whether  tensile  or  com- 
pression, is  easily  learned  by  inspection,  and  in  Fig.  65  the  mem- 
bers under  compression  have  all  been  drawn  in  heavy  lines, 
leaving  the  tension  members  in  light  lines.  This  forms  a  very 
good  way  of  designating  the  character  of  load  and  one  which  is 
not  easily  mistaken.  The  following  table  shows  the  usual  man- 
ner of  making  up  a  stress  record  from  which  the  size  of  the 
necessary  truss  members  may  be  readily  computed,  their  length 
being  known  from  a  large  drawing,  or  they  may  be  found 
directly  by  computation,  a  combination  of  the  two  methods  being 
used  in  practical  work. 

STRAIN   RECORD. 


Member 

Stress 

be 
-1756 

cd 

-578 

de 
-1178 

dd, 

-818 

d^ 
-1178 

cA 

-578 

biCj 

-1756 

aiC! 

-1227 

ac 
-1227 

Having  obtained  this  data,  the  millwright  may  construct  the 
truss  in  accordance  therewith,  and  he  must  be  sure  to  put  nails  or 
bolts  enough  in  the  joints  of  the  truss  to  withstand  the  several 
strains  laid  down  as  above.  It  requires  a  certain  number  of  spikes 
to  carry  a  load  of  1225  pounds.  Just  how  many  is  an  open  question, 
and  some  light  will  be  shed  upon  that  problem  in  a  later  chapter. 
The  figures  given  above  were  obtained  by  means  of  the  slide  rule, 
and  the  measurements  were  made  upon  a  very  small  scale  without 
the  expectation  that  they  are  accurate  enough  for  steel-work. 
They  are  intended  merely  to  acquaint  the  millwright  with  one 
method  of  calculating  roof  strains  and  trusses  for  carrying  the 
same,  in  order  that  he  may  have  a  little  "know-how"  at  hand  when 
necessity  calls,  also  that  he  may  become  interested  in  the  fasci- 
nating study  of  trusses,  thereby  adding  to  his  working  knowledge 
and  to  his  value  to  his  employer — and  incidentally  increasing  his 
cash  account  by  drawing  a  better  salary  on  account  of  the  acquired 
knowledge. 


154 


M1LLWRIGHTING 


EVOLUTION  OF  THE  TRUSS. 

Having  found  how  to  calculate  the  elements  of  a  simple  truss 
as  shown  by  Fig.  57,  it  is  proper  that  a  hint  should  be  given 
regarding  the  development  of  more  elaborate  trusses.  In  the  form 
shown  by  Fig.  57  and  several  other  drawings,  the  truss  is  simply 
a  large  letter  A.  If  it  be  necessary  to  erect  a  truss  without  build- 
ing it  to  so  great  a  hight,  some  means  must  be  devised  for  cut- 
ting off  the  top  of  the  truss  and  still  retain  the  same  supporting 
power  which  was  possessed  by  the  members  thus  dispensed  with. 
Accordingly,  as  shown  by  Fig.  67,  the  peak  or  apex  of  the  truss 


\ 


\ 


FIG.  67.— EVOLUTION  OF  THE  HOWE  TRUSS. 

was  cut  off  to  the  hight  desired,  and  the  A-portion  of  the  sup- 
porting timbers  a  and  b,  were  simply  cut  up  into  short  portions 
and  disposed  at  the  same  angle  they  previously  occupied  in  the 
spaces  d  e,  e  f,  f  g,  g  h,  etc.,  and  the  resulting  design  is,  after 
the  rods  have  been  shortened  to  the  lengths  e  c,  f  f,  g  g,  etc,  a  form 
of  the  Howe  truss.  An  upper  chord,  a  h,  was  added  and  carried 
through  c,  where  the  unchanged  application  of  the  A-frame  is 
shown  before  cutting  it  down  into  a  Howe  truss. 

Sometimes  the  A-frame  truss  was  inverted,  as  in  Fig.  68, 
owing  to  conditions,  and  the  span  was  supported  upon  the  posts 
and  strain-timber,  rod  or  cable,  as  shown  at  b  c  L  When  the  V-sup- 


ROOF  TIMBERING  AND  TRUSSES 


155 


port  got  in  the  way,  it  was  cut  off,  as  shown,  at  c  d,  the  posts  i  j  k  I 
cut  off  and  tie-rods  e  f  g  h  put  in  position,  a  top  chord  d  added 
and  the  V-frame  caterpillar  came  forth  a  full-fledged  Pratt  truss. 


7f 

I 


\ 


X 


\ 


H 


\ 


FIG.  68.— EVOLUTION  OF  THE  PRATT  TRUSS. 

The  strains  in  both  these  trusses,  also  in  all  modifications  of  these 
forms,  and  in  all  other  forms  and  their  variations,  may  be  quickly 
calculated  by  means  of  the  strain  diagram  shown  by  Fig.  66 — or 
another  diagram  made  to  fit  the  structure. 

FLAT  ROOFS. 

Roofs  which  are  to  be  covered  with  "tar  and  gravel''  as  it  is 
commonly  called,  or  "composition"  as  it  would  be  technically 
termed,  should  never  have  a  pitch  of  more  than  %  inch  to  the  foot, 
and  a  great  deal  less  will  answer  most  purposes.  For  this  kind 
of  roof  the  truss,  in  some  form  or  other,  is  almost  a  necessity, 
unless  the  post  and  beam  method  of  framing  can  be  followed  out. 

THE  COMPOSITION  ROOF. 

The  time-honored  "tar  and  gravel"  composition  roof  is  very 
desirable  for  mill  construction.  There  is  no  lost  room  under  a 
roof  of  this  kind,  and  the  heavy  roof  timbering  necessary  is  often 
useful  for  hanging  small  counter-shafts  and  for  the  attachment 


156 


MILLWRIGHTING 


of  elevators,  conveyors,  etc.  The  timbering  for  this  floor  should 
be  ample  to  prevent  its  springing  under  load,  thereby  cracking 
the  tarred  paper  upon  which  the  tightness  of  the  roof  depends. 
The  sheathing  should  be  tongued  and  grooved  and  well  laid  with 
no  open  cracks  or  knot  holes. 

Three  thicknesses  of  tarred  felt  should  be  used,  the  roof  first 
being  covered  with  a  layer  of  resin-sized  felt  lapped  a  couple  of 
inches  and  fastened  with  tacks  sufficient  to  hold  it  in  place.  It 
must  be  stated  that  this  covering  of  paper  is  seldom  used  except 
upon  concrete  roofs,  and  even  then  it  is  often  omitted,  especially 
in  contract  work. 

LAYING  A  COMPOSITION  ROOF. 

The  method  usually  employed  in  laying  these  roofs  is  shown 
by  Fig.  69,  the  first  course  of  felt  being  about  12  inches  wide  as 
shown  at  a.  Some  roofers  double  a  course  back  12  inches  and  lay 


FIG.    69.— LAYING    COMPOSITION    ("TAR    AND    GRAVEL")     ROOFING. 

it  with  the  double  edge  at  the  bottom,  but  it  seems  preferable  to 
cut  one  course,  lay  the  12-inch  strip  at  a  and  the  24-inch  strip 
over  the  12-inch  one,  as  shown  at  b.  Next,  a  full  width  or  36-inch 


ROOF  TIMBERING  AND  TRUSSES  157 

strip  of  tarred  paper  is  unrolled  as  shown  at  c,  and  other  strips 
d,  e,  f,  g,  etc.,  are  unrolled  as  shown,  each  strip  lapping  two-thirds 
its  width  upon  the  preceding  strip,  thus  securing  three  thicknesses 
of  the  felt  laid  "clapboard  fashion"  from  eaves  to  middle  of 
roof. 

To  fasten  the  tarred  paper  some  hot  tar  is  run  under  each 
lower  edge  of  the  paper,  the  conical  dipper  being  so  made  that 
it  may  be  pushed  along  under  the  edge  of  the  paper  leaving  a  thin 
trail  of  hot  tar  as  the  tool  progresses  from  end  to  end  of  the  roof. 
Next,  a  strip  of  board  about  %x2^  inches  is  nailed  around  the 
edge  of  the  roof  after  the  paper  has  been  thoroughly  swabbed  with 
hot  tar.  After  the  strip  is  in  place  it  is  also  given  a  coat  of  hot  tar, 
and  clean  gravel  is  spread  over  the  hot  tar  on  the  felt  to  serve  as  a 
protection  for  that  substance  and  to  prevent  its  running  off  as 
freely  when  the  hot  sun  gets  in  its  work  in  summer.  If  a  roof 
be  given  a  pitch  greater  than  %  inch  to  the  foot,  the  tar  will  run 
in  spite  of  the  gravel  coating;  %  inch  to  the  foot  is  plenty  steep 
enough  for  composition  roofs. 

It  is  of  great  importance  that  the  tarred  paper  be  of  good 
quality,  for  upon  its  quality  depends  the  waterproofing,  and 
nothing  is  more  aggravating  than  leaks  in  a  roof,  especially  in  a 
new  roof.  For  work  which  is  required  to  be  the  best  possible,  irre- 
spective of  expense,  it  is  the  custom  to  place  a  second  layer  of 
felt  over  the  triple  layer.  The  second  layer  is  laid  more  to  the 
weather  than  the  first  layer — sometimes  20  or  22  inches — and  it 
is  then  mopped  with  hot  tar,  and  another  coat  is  flowed  on  just 
before  the  gravel  is  spread. 

Thick  felt  ranging  from  1/16  to  3/16  inch  can  be  obtained, 
all  covered  with  fine  gravel,  and  only  needing  to  be  placed  on  the 
roof,  nailed  in  place,  and  the  laps  made  with  a  composition  which 
comes  inside  the  roll.  This  material  makes  a  very  desirable  roof- 
ing and  it  stands  well  in  hot  climates  as  well  as  in  dry  cold  lati- 
tudes. Sometimes  layers  of  felt  are  alternated  with  layers  of 
pulverized  slate  and  asphalt.  This  material  can  be  used  upon 
roofs  so  steep  that  tar  and  gravel  will  not  stay  on  them.  The 
"plastic  slate  roofing,"  as  it  is  called,  may  be  applied  with  a 
trowel  directly  to  wood  or  to  masonry  surfaces,  and  it  adheres 
so  strongly  that  tight  work  can  be  made  with  but  little  use  for 
metal  flashing  which  is  so  necessary  with  other  roofs. 


158 


MILLWRIGHTING 


TIN  AND  COPPER  ROOFS. 


Tin  makes  the  lightest  roof  of  any  material  in  use  for  water- 
proofing. It  is  also  the  cheapest,  if  the  tongued  and  grooved 
sheathing  necessary  underneath  is  not  considered.  When  the 
millwright  has  to  look  after  roofers  who  are  laying  tin,  he  should 
see  that  no  inferior  plate  is  used.  It  is  easy  to  substitute  lighter 
plate,  but  the  millwright  has  the  remedy  at  hand  all  the  time.  He 
has  only  to  weigh  a  square  foot  of  the  tin  and  if  it  weighs  8 
ounces  he  may  know  that  "one  cross"  (IX)  tin  is  being  used. 
If  the  12xl2-inch  piece  should  weigh  10  ounces,  then  "1C"  would 
be  the  grade  of  that  piece  of  tin.  Lighter  than  8  ounces  to  the 


FIG.   70.— LAYING  A   TIN   ROOF. 

square  foot  is  not  good'  enough  tin  to  pay  for  putting  on  a  roof. 

While  standing  seams  are  used,  they  are  for  show  more  than 
for  use,  though  on  large  roofs  they  will,  it  is  claimed,  take  care 
of  expansion  better  than  when  the  seams  are  hammered  flat  and 
soldered.  But  as  the  standing  seams  run  only  one  way  of  the 
roof,  while  the  seams  in  the  other  direction  are  all  hammered 
flat  and  soldered,  the  writer  fails  to  see  any  benefit  to  be  derived 
from  unsoldered  seams  standing  1  inch  above  the  roof  in  one 
direction  only. 

Never  allow  a  tin  roof  to  be  fastened  to  the  sheathing  by 
nailing  through  the  tin,  either  in  the  lap  or  anywhere  else. 
Always  insist  upon  the  tin  being  put  together  in  the  shop  into 


ROOF  TIMBERING  AND  TRUSSES  159 

strips  as  long  as  the  roof  horizontally,  or  as  long  as  the  strips 
can  be  handled  easily.  Then  lay  the  strips  as  shown  at  b  and  c, 
Fig.  70  and  let  cleats  e  e  e  e  be  placed  as  shown,  every  14  or  15 
inches,  and  locked  under  the  front  edge  of  the  tin.  Let  each  cleat 
be  nailed  as  closely  as  convenient  to  the  edge  of  the  sheet  to 
which  the  cleat  is  hooked.  Then  when  the  next  sheet  is  in  place 
and  the  seams  hammered  down  over  the  cleats  it  will  be  impos- 
sible for  the  cleats,  which  are  cut  about  Iy2x3y2  inches,  to  pull 
out.  Neither  can  the  expansion  of  the  tin  pull  it  free  of  the  nail- 
heads,  something  very  apt  to  happen  when  the  tin  is  nailed 
direct  to  the  roof. 

See  that  the  long  strips  are  pressed  snugly  home  when  in 
place,  as  shown  at  c ;  and  before  hammering  down  the  seam  c 
put  all  the  cleats  in  place ;  see  that  the  last  strip  in  place  lies 
straight  and  bears  fully  against  the  sheet  it  is  locked  with.  After 
the  seams  have  been  hammered  down,  as  at  a  and  b,  see  that  they 
are  soldered  well,  that  no  holes  are  left  and  that  no  acid  shall  be 
used  in  soldering.  Use  resin,  nothing  else,  for  a  flux  when 
soldering  a  roof.  Acid  makes  it  some  easier  for  the  tinsmith, 
but  it  is  bad  for  the  roof  and  is  apt  to  cause  rust.  A  very  good 
way  to  use  resin  and  to  prevent  it  from  being  blown  away  by 
the  wind  is  to  pound  the  resin  in  a  stout  bag,  or  run  it  through 
a  coffee  mill  or  otherwise  pulverize  it  so  it  will  pass  through 
ordinary  wire-cloth  fly  screening.  Then  place  some  of  the  resin 
in  gasoline  until  that  liquid  will  dissolve  no  more.  Apply  the  dis- 
solved resin  with  a  small  brush  or  a  bit  of  cloth  wound  around 
a  wire  or  a  stick.  The  gasoline  evaporates  quickly,  leaving  the 
resin  fixed  just  where  it  is  needed. 

Where  tin  is  turned  up  against  other  parts  of  the  building, 
such  as  chimneys,  skylights,  or  other  buildings,  insist  upon  its 
being  turned  up  at  least  4  inches  and  then  capped  with  lead  or 
zinc  flashing  well  cemented  into  the  walls  or  chimney  in  question. 
For  a  first  class  job,  have  the  tin  painted  before  it  is  placed  on 
the  roof,  and  do  not  allow  it  to  be  painted  after  soldering  until  a 
storm  or  two  has  washed  the  tin  thoroughly  and  slightly  rusted 
it.  The  paint  will  adhere  much  better  when  thus  applied.  All 
resin  should  be  thoroughly  cleaned  from  the  tin  before  painting 
the  roof. 


160  MILLWRIGHTING 

REPAIRING  LEAKY  TIN  ROOFS. 

The  millwright  sometimes  has  repairs  to  make  on  tin  roofs 
which  are  full  of  holes  and  quite  beyond  even  the  possibility  of 
soldering.  A  quick  way  of  making  repairs  to  roofs  of  this 
kind  is  to  procure  a  few  pounds  of  portland  cement  and  scatter 
it  on  the  roof.  With  a  broom  sweep  the  cement  back  and  forth 
until  some  of  it  has  penetrated  into  every  hole  that  exists  in  the 
tin.  Then  with  a  common  watering  pot,  fitted  with  a  very  fine 
rose  sprinkler,  go  carefully  over  the  entire  roof,  wetting  it 
thoroughly  but  not  wet  enough  so  the  water  will  run.  "Just  a 
heavy  fog"  is  exactly  what  is  wanted — enough  to  dampen  the 
cement  in  the  holes  it  has  found  its  way  into. 

Once  the  cement  has  been  well  dampened,  go  away  and  leave 
it  until  the  next  day ;  then  paint  the  roof  with  some  good  elastic 
paint,  or  elastic  roofing,  and  the  holes  will  be  so  thoroughly 
closed  that  the  roof  may  not  leak  again  for  a  year  unless  some- 
thing happens  to  strain  the  roof  sufficient  to  break  the  cement  in 
the  holes. 

COPPER  ROOFING. 

Copper  should  be  applied  in  about  the  same  manner  that  tin 
is  put  on,  and  the  strips  of  copper  can  be  had  of  considerable 
size — as  long,  in  fact,  as  the  tinner  can  find  length  of  machines 
for  the  bending  and  locking  or  seaming.  Probably  the  millwright 
will  have  but  very  little  to  do  with  copper  roofing,  for  although 
it  makes  a  most  durable  roof  its  first  cost  is  often  prohibitive 
unless  for  the  very  best  buildings.  It  is  seldom  that  a  mill  is 
found  with  a  copper  roof. 

SLATE  ROOFING 

It  will  not  pay  to  use  slate  on  roofs  having  less  pitch  than 
5  inches  to  the  foot,  though  slates  can  be  laid  tightly  on  a  surface 
of  almost  no  pitch  at  all.  This,  however,  means  the  expense  of 
bedding  each  slate  in  cement.  Even  with  ordinary  half -pitch 
roofs  (half-pitch  means  that  the  hight  of  the  roof  is  one-half 
the  width  of  the  building)  the  slates  in  valleys,  for 'at  least  two 
feet  on  each  side,  also  above  gutters,  should  be  laid  in  good  elastic 
cement.  The  trade  calls  this  "rendering,"  and  it  should  also  be 
done  on  all  vertical  pieces  of  slating  and  on  the  tops  of  ridges 


ROOF  TIMBERING  AND  TRUSSES  161 

and  hips  for  at  least  a  foot  in  width.  This  is  to  prevent  water 
from  backing  up  under  the  slates. 

No  slate  should  be  permitted  to  be  laid  without  two  nails  in 
it,  and  the  tip  of  every  slate  should  be  lapped  by  the  second 
course  at  least  3  inches.  The  nails  should  be  3-penny  or  4-penny, 
with  large  heads  and  should  be  driven  so  carefully  that  they  do 
not  either  crack  the  slates  or  let  them  rattle,  and  no  nail  should 
be  used  which  is  not  tinned,  galvanized,  or  made  of  copper. 

It  pays  to  use  copper  gutters  on  slate  roofs  and  to  put  in  good 
open  gutters  at  least  18  inches  wide.  A  strip  of  metal  may  be 
put  on  the  roof  and  nailed  to  the  sheathing,  the  slates  cut,  nailed 
and  "rendered"  and  lapping  over  the  metal.  The  writer,  how- 
ever, much  prefers  to  put  in  gutters  made  of  separate  strips  of 
metal,  laying  them  in  with  the  slates  and  overlapping  the  strips 
to  form  the  gutter  instead  of  nailing  a  single  sheet  solid  to  the 
sheathing.  With  the  loose,  lapped  sheets  expansion  takes  care  of 
itself. 

% 

MONITORS  AND  SKYLIGHTS. 

When  roof  lighting  is  to  be  provided,  and  especially  during 
the  construction  of  skylights  and  "monitors"  the  millwright  will 
do  well  to  keep  a  very  close  watch  on  the  manner  of  connecting 
or  attaching  the  super-structures  to  the  mill  roof.  There  is  no 
worse  leak  to  handle  than  one  under  a  skylight  or  monitor.  Unless 
sufficient  strengthening  is  put  into  the  roof  directly  under  the 
wall  or  combing  of  the  superstructure  there  is  sure  to  be  more  or 
less  settling  of  the  roof,  the  boards  of  which  lie  nearly  flat.  The 
combing  of  a  skylight  stands  on  edge,  and  it  will  not  settle  with 
the  roof,  but  stands  stiffly  upon  the  supporting  beams  or  trusses 
and  permits  the  roof  sheathing  to  sag  away  from  it. 

The  water  very  quickly  finds  its  opportunity  in  a  case  as 
above,  and  leaks  will  surely  occur  and  persist  in  remaining  in 
evidence  no  matter  what  attempts  are  made  at  repairs.  See  that 
the  necessary  headers  are  put  in  below  all  monitors,  deck-stories, 
skylights  and  hatches  to  make  perfectly  rigid  the  connection 
between  the  roof  sheathing  and  the  wall  or  combing  of  the  struc- 
ture erected  upon  the  roof.  In  more  than  one  instance  the  writer 
has  been  forced  to  put  in  timbers  to  carry  the  weight  of  monitor 
walls,  and  the  timbers  once  in  place,  the  leakage  problem  was 


162  MILLWRIGHTING 

settled  once  for  all  by  boring  holes  through  the  timbers  and  the 
frames  qf  monitors  or  skylights  into  which  %-inch  bolts  were 
placed  and  screwed  home.  The  same  trouble  has  been  more  than 
once  experienced  by  a  millwright  in  keeping  the  sides  and  bottom 
of  a  flume  from  springing  apart  under  the  water  pressure. 

"SAW-TOOTH"  LIGHTING. 

The  same  trouble,  as  noted  in  the  foregoing,  is  to  be  guarded 
against  when  buildings  are  constructed  to  be  lighted  from  the 
roof  on  the  so-called  "saw-tooth"  plan.  That  is,  the  top  of  the 
building  is  cut  up  into  small  inclined  roofs,  the  wall  of  which  is 
vertical  or  nearly  vertical  on  the  north  side  of  the  building,  while 
the  remaining  side  of  each  narrow  roof  section  inclines  down- 
ward to  the  bottom  of  the  adjacent  nearly  vertical  wall.  Each  of 
these  walls  is  to  be  composed  almost  entirely  of  glass  so  as  to 
give  a  large  volume  of  "north  light"  and  to  the  exclusion  of 
almost  all  the  direct  rays  of  the  sun. 

While  the  saw-tooth  system  gives  most  excellent  lighting 
effects,  the  millwright  should  pay  close  attention  to  the  manner  in 
which  the  window  wall  and  the  roof  of  the  succeeding  saw- 
tooth are  joined  together.  It  is  very  apt  to  develop  the  old  trouble 
met  with  in  placing  a  skylight  on  a  roof  without  proper  carrying 
timbers  underneath,  resulting  in  the  roof  settling  away  from  the 
vertical  member  of  the  "saw-tooth."  It  is  then  "up  to"  the  mill- 
wright building  inspector  to  see  that  sufficient  timbering  is  placed 
underneath  the  root  of  each  "tooth"  that  the  inclined  portion  can 
never  sag  away  from  the  vertical  portion  of  the  structure. 


CHAPTER  X. 

STRENGTH  OF  MATERIALS. 

How  much  load  will  a  %-inch  bolt  carry  safely?  That  is  a 
question  the  millwright  has  more  than  once  asked  himself  when 
setting  up  machinery  or  hanging  shafting.  If  a  millwright  should 
come  to  work  some  morning  and  find  the  entire  steam  boiler, 
setting  and  all,  to  the  extent  of  18  tons  hanging  overhead  sus- 
pended by  a  single  %-inch  rod,  that  millwright,  or  any  other 
sane  man,  would  go  a  long  ways  around  before  he  would  pass 
underneath  the  load  thus  suspended.  And  yet  the  %-inch  rod 
might  hold  up  the  18-ton  load,  and  again  it  might  not.  If  two 
rods  were  used  to  carry  the  load,  making  nine  tons  apiece,  the 
millwright  would  still  look  sidewise  several  times  before  trust- 
ing himself  beneath  such  a  deadfall. 

Should  the  steel  in  the  suspension  rod  be  of  a  strength  of 
60,000  pounds  to  the  square  inch  of  cross  section,  it  would  just 
carry  the  load  of  18  tons,  as  the  following  calculations  will  show : 

Tensile  strength  of  a  bar  1x1  inch= 60,000  pounds. 

Area  of  a  circle  %-inch  dia. :  0.875X0.875X0.7854—0.6  sq. 
inch. 

60,000X0.6=36,000  pounds=18  tons. 

But  nobody  knows  exactly  the  strength  of  a  steel  rod  until 
that  rod  has  been  pulled  apart  in  a  testing  machine  and  the  load 
necessary  to  break  the  rod  has  been  carefully  noted.  The  steel 
manufacturer  cannot  tell  beforehand  what  is  the  exact  strength 
of  the  steel  he  is  making.  Should  the  .percentage  of  carbon  in 
the  steel  vary  ever  so  little  it  causes  a  corresponding  variation  in 
the  strength  of  the  finished  product. 

Steel  which  will  harden  is  not  desirable  for  bolts  or  rods, 
and  if  the  percentage  of  carbon  in  any  steel  amounts  to  4/10  of 
one  per  cent.,  that  steel  will  harden  sufficiently  to  make  good  cut- 
ting tools.  Ordinary  cast  steel  contains  about  that  amount  of 
carbon.  Steel  containing  carbon  enough  to  harden  becomes 

163 


164  MILLWRIGHTING 

so  treacherous  in  its  behavior  that  it  is  not  desirable  for  struc- 
tural work  or  for  forgings.  High  carbon  steel  when  it  does  fail 
does  so  with  a  snap,  while  the  low  carbon  steels  fail  by  first 
stretching  gradually  under  about  one-half  their  breaking  load. 

The  steel  manufacturer  can  never  tell  exactly  beforehand  how 
much  carbon  a  certain  lot  of  steel  will  contain.  He  can  deter- 
mine exactly,  after  the  steel  is  made,  just  the  amount  of  carbon 
it  does  contain,  but  to  determine  that  matter  exactly  beforehand 
is  beyond  the  power  of  the  manufacturer.  Possibly  there  may  be 
defects  in  the  making  of  the  steel  which  cannot  be  seen  how- 
ever close  an  examination  the  steel  is  subjected  to,  therefore 
the  millwright  is  unable  to  trust  any  steel  or  any  other  material 
as  well  with  the  full  breaking  load  on  account  of  the  unknown 
condition  noted  above. 

The  elastic  limit  of  soft  steel  is  about  one-half  its  breaking 
load.  That  is,  steel  will  begin  to  stretch  when  loaded  with  about 
one-half  what  is  required  to  break  it.  The  millwright,  then, 
cannot  use  even  one-half  the  known  strength  of  any  piece  of  steel 
on  account  of  possibly  pulling  the  metal  out  of  shape  by  the  load 
placed  upon  it.  "But,"  the  millwright  now  asks :  "What  load 
can  I  safely  place  on  a  steel  rod  which  begins  to  stretch  under 
8  tons  pull,  and  breaks  just  above  16  tons  load?" 

FACTOR  OF   SAFETY. 

To  safely  allow  for  the  possible  variation  of  carbon  in  the 
steel,  for  the  presence  of  possible  (not  probable)  defects  in  manu- 
facture of  the  steel,  and  also  to  allow  for  the  variation  in  the  load 
above  the  supposed  amount,  it  is  customary  to  use  only  one-tenth 
to  one-fifth  the  breaking  load  as  the  safe  working  load.  For  ordi- 
nary places  where  the  load  is  steady,  as  in  steam  boilers  and  bolts, 
rods  and  other  structural  metal  work,  5  is  the  usual  factor  of 
safety,  but  for  certain  parts  of  bridges  and  certain  portions  of 
machines  where  the  load  is  not  steady  but  takes  the  nature  of  a 
blow,  then  only  one-tenth  the  breaking  load  should  be  placed 
upon  the  metal  and  its  factor  of  safety  becomes  10. 

Thus,  in  the  case  of  the  rod  which  sustains  18  tons,  or  breaks 
under  that  load  to  the  square  inch,  accordingly  as  the  carbon 
varies  a  few  tenths  of  one  per  cent. — only  one-fifth  of  the  18  tons 
should  be  used  as  a  safe  load,  and  3  6/10  tons,  or  7200  pounds, 


OF  THE 

UNIVERSITY 

OF 


STRENGTH  OF  MATERIALS  165 

is  all  that  should  be  placed  upon  the  rod  in  question.  But  should 
the  rod  be  used  for  a  bolt  even  less  load  should  be  placed  upon 
it  for  the  reason  that  a  portion  of  the  metal  is  cut  away  when  the 
bolt  is  threaded.  The  tables  of  bolt  threads  give  0.731  inch  as  the 
diameter  of  the  bolt  at  the  bottom  of  the  thread.  This  diameter 
corresponds  to  a  cross-sectional  area  of  0.42  square  inches,  and 
0.42x60,000-^5=5040,  meaning  that  no  %-inch  bolt  should  ever 
be  put  in  to  carry  more  than  5000  pounds  tensile  strain.  In 
boiler  bracing,  not  even  that  load  is  allowed,  for  the  require- 
ments of  The  Hartford  Steam  Boiler  Inspection  and  Insurance 
Company  recommend  that  no  boiler  brace,  1  inch  in  diameter, 
shall  be  placed  to  carry  more  than  5000  pounds. 

TRANSVERSE  STRENGTH. 

The  calculations  for  the  strength  of  a  bolt,  above  noted,  are 
all  for  a  direct  pull  upon  the  metal.  There  are  other  strains  to 
which  the  metal  is  subject  in  machines  and  power  transmissions. 
When  a  rod  is  laid  upon  two  supports  and  must  carry  a  load 
placed  on  the  rod  between  those  supports,  then  the  load  is  said 
to  be  transverse,  and  the  amount  of  load  which  the  rod  can  carry 
depends  entirely  upon  the  tensile  strength  of  the  material  of 


FIG.  71.— TRANSVERSE  STRENGTH. 

which  the  rod  is  composed  and  the  manner  in  which  the  rod  is 
supported.  This  is  shown  by  Fig.  71,  in  which  a  rod  is  shown 
resting  upon  two  supports,  c  and  d,  with  a  load  applied  at  e,  mid- 
way between  the  supports.  If  sufficient  load  is  applied,  the  rod  is 
bent,  either  by  stretching  at  a  or  by  upsetting,  or  compressing  at  b. 
Calculating  the  strength  of  beams  or  levers — they  are  the  same 
as  far  as  calculations  are  concerned — is  about  the  worst  piece  of 
mathematics  the  millwright  will  have  to  contend  with.  The  calcu- 
lating of  tensile  strength  is  easy.  Compression  and  shearing  cal- 


166 


MILLWRIGHTING 


dilations  are  also  very  simple,  but  the  transverse  strength  of  a 
beam  is  a  hard  thing  to  handle.  The  calculation  itself  is  not 
hard,  but  to  understand  why  it  is  done  as  indicated — that  is  where 
the  hard  part  comes. 

THE  STRENGTH  OF  A  BEAM. 

It  must  be  understood  that  with  one  beam  twice  as  wide  as 
another  the  larger  beam  is  just  twice  as  strong,  but  a  beam  twice 
as  deep  as  another  is  more  than  twice  as  strong.  Such  a  beam 
would  be  a  good  deal  more  than  twice  as  strong.  In  fact,  such  a 
beam  would  be  eight  times  as  strong.  The  strength  of  a  beam  as 
regards  its  depth  increases  according  to  the  cube  of  that 
dimension. 

Fig.  72  illustrates  this  matter:  The  beam  A  has  a  certain 
strength  which  will  be  measured  by  its  width,  multiplied  by  the 
cube  of  its  depth.  Thus,  2X2X2X2=16.  The  beam  B,  which 
is  twice  as  wide  as  A,  has  its  transverse  strength,  or  its  carry- 


I- — i — ^ 


c 


FIG.   72.— THE   STRENGTH   OF  BEAMS. 


ing  power,  measured  by  4X2X2X2=32,  thus  beam  B  is  just 
twice  as  strong  as  beam  A.  But  beam  C  is  the  same  size  as  beam 
B,  with  the  difference  that  it  has  been  turned  up  edgewise,  thus 
making  it  the  same  width  as  beam  A  and  just  twice  as  deep. 
The  strength  of  the  beam  in  this  position  is  2X4X4X4=128,  or 
eight  times  as  strong  as  beam  A.  Thus,  doubling  the  depth,  gives 

eight  times  the  strength,  and  the  expression  for  any  beam  is  :^— , 

where  w=width  of  beam, 
d=depth  of  beam, 
l=length  of  beam. 

Thus  the  measure  of  any  beam,  and  the  manner  in  which  one 
beam  shall  be  compared  with  another  beam,  is  the  width  multi- 


STRENGTH  OF  MATERIALS  167 

plied  by  the  square  of  the  depth  and  the  product  divided  by  its 
length. 

Whenever  the  millwright  has  occasion  to  use  the  books  of  any 
of  the  steel  companies,  either  the  handbooks  of  Carnegie,  Pencoyd 
Phoenix,  etc.,  and  attempts  to  take  therefrom  the  dimensions  of 
a  beam  to  carry  a  given  load,  he  will  be  confronted  by  a  most 
exasperating  array  of  figures,  given  in  table  form  and  headed : 
IrzrMoment  of  Inertia. 

T= Distance  from  Neutral  Axis  to  Farthest  Fiber. 

X=— ^-Section  Modulus. 

A=Area  of  Section. 

The  best  thing  the  millwright  can  do  is  to  "get  next"  to  these 
things  and  find  out  the  meaning  and  the  use  of  "moment  of 
inertia,"  "neutral  axis,"  "extreme  fiber,"  "section  modulus"  and 
"unit  stress,"  for  nothing  can  be  done  with  the  excellent  handbooks 
in  question  without  a  little  knowledge  of  the  things  mentioned, 
and  once  that  "know-how"  is  acquired  he  will  have  no  further  diffi- 
culty with  beams  or  levers.  He  will  be  able  to  figure  the  neces- 
sary strength  of  a  48-inch  crowbar  or  a  24-inch  I-beam,  a  floor- 
joist,  a  shaft  bridgetree  or  the  frame  of  a  machine. 

In  the  rod  shown  by  Fig.  71,  it  is  a  fact  that  no  permanent 
bending  can  take  place  until  it  has  been  loaded  beyond  its  elastic 
limit,  whatever  that  is,  and  it  is  evident  that  in  steel  the  compres- 
sive  strength  is  much  greater  than  the  tensile  strength,  therefore 
the  rod  must  bend  by  stretching  at  a.  It  was  shown  under  ten- 
sile strength  that  the  elastic  limit  of  steel  was  about  half  its  break- 
ing, or  ultimate  strength,  so  that  if  the  load  applied  at  e  be  not 
sufficient  to  strain  the  metal  at  a  or  no  more  than  30,000  pounds 
to  the  square  inch  of  section,  then  no  permanent  bending  can  take 
place.  It  is  evident  that  the  stretching  and  compressing  meet 
somewhere  in  the  distance  between  a  and  e,  which  is  called  the 
neutral  axis,  and  its  location  is  in  the  center  of  gravity  of  the  cross 
section  of  the  rod.  In  this  case  it  is  in  the  center,  along  the  line  /. 

The  strength  of  any  fiber  at  a  must  not  be  exceeded  by  the 
strain  put  upon  it,  or  the  whole  number  of  fibers  will  be  broken, 
one  after  the  other,  hence  the  measure  of  the  load  which  can  be 
applied  to  any  rod  as  in  Fig.  71  must  be  within  the  safe  tensile 
load  of  any  fiber  at  a.  This  load  is  called  the  "extreme  fiber 


168  MILLWRIGHTING 

stress"  and  its  amount  is  determined  by  the  distance  of  the  fiber 
from  the  neutral  axis  /.  It  is  evident  that  were  the  rod  twice  as 
large  as  at  present  the  fiber  at  a  would  be  twice  as  far  from  /; 
consequently  it  would  have  twice  the  leverage  as  at  present  and 
the  tensile  strength  of  the  material  could  carry  twice  the  present 
load  because  it  would  have  twice  the  leverage  to  do  it  with. 

THE  MOMENT  OF  INERTIA. 

It  is  evident  that  while  the  fibers  at  a,  Fig.  73,  can  carry  a 
considerable  load  owing  to  their  distance  from  the  neutral  axis, 
the  fibers  at  the  axis  can  carry  but  very  little  load  owing  to  the 
very  short  leverage  which  can  be  exerted  by  them.  To  find  how 
much  load  all  the  fibers  in  any  section  can  carry  requires  more 
mathematics  than  can  be  given  here,  and  it  is  sufficient  to  state 
that  the  sum  of  the  strain-carrying  capacity  of  every  fiber  in  the 
rod  is  called  the  "moment  of  inertia,"  and  it  varies  according  to 
the  shape  of  the  section  and  has  nothing  to  do  with  the  material 
of  which  the  section  is  composed,  neither  does  the  length  of  that 
body  make  any  difference  in  the  moment  of  inertia. 

The  term  "moment  of  inertia"  is  in  itself  the  most  misleading 
term  the  millwright  will  encounter  in  all  his  business.  It  has 
nothing  whatever  to  do  with  inertia  in  any  way,  shape  or  manner. 
Moment  of  inertia  may  well  be  called  the  "fourth  dimension" 
teachers  occasionally  puzzle  students  with.  For  instance,  if  we 
multiply  together  two  dimensions,  say  length  and  breadth,  we 
obtain  an  area.  If  three  dimensions,  length,  breadth  and  thick- 
ness are  multiplied  together,  we  obtain  a  volume.  If  four 
dimensions  are  multiplied  together,  length,  breadth,  and  the  square 
of  the  distance  from  some  other  point,  then  we  obtain  the  "moment 
of  inertia." 

In  finding  the  moment  of  inertia,  we  take  the  area  of  any  small 
portion  of  the  cross  section  of  the  rod,  multiply  the  area  of  that 
small  section  by  its  distance  from  the  neutral  axis  of  the  rod, 
and  thus  obtain  the  moment  of  that  small  area.  But  to  find  the 
moment  of  inertia  of  the  entire  section,  or  the  sum  of  all  the 
moments  of  the  small  sections,  we  must  multiply  the  area  of 
the  entire  section  by  the  square  of  the  distance  from  the  axis. 
In  the  case  of  a  square  rod,  as  at  A,  Fig  72,  the  moment  of  inertia 
will  be  the  fourth  power  of  the  side  of  the  rod,  divided  by  12, 


STRENGTH  OF  MATERIALS  169 

thus :  The  moment  of  inertia  of  a  rod  2  inches  square  would  be 
2X2X2X2-^-12=1.33.  For  shape  B,  the  moment  of  inertia  will 
be  4X2X2X2-1-12=2.66.  For  shape  C,  the  moment  of  inertia 
will  be  2X4X4X4-^12=10.66. 

EXTREME  FIBER. 

Having  found  that  the  resisting  value  of  all  the  separate 
fibers  in  the  2x4-inch  section  is  10.66,  it  is  in  order  to  see  what  load 
may  be  applied  without  causing  trouble  in  the  fibers  farthest  away 
from  the  neutral  axis.  As  the  section  is  2x4  inches  it  is  very  evident 
that  none  of  the  fibers  at  a,  Fig.  72,  can  be  more  than  2  inches 
from  the  neutral  axis  /,  therefore  the  distance  of  the  extreme 
fibers  is  2  inches  in  the  example,  and  in  calculating  the  load  which 
can  be  applied  to  the  beam  it  must  be  considered  that  the  fiber 
furthest  away  from  the  neutral  axis  is  2  inches,  and  no  load 
must  be  applied  to  those  fibers  which,  when  calculated  by  the  lever- 
age (moment)  of  that  force  and  the  leverage  of  the  fiber,  cannot 
be  carried  by  the  fiber  without  loading  it  beyond  its  elastic  limit, 
or  to  the  proper  factor  of  safety.  Thus,  in  the  beam  2  inches  deep, 
the  distance  of  the  extreme  fiber  from  the  neutral  axis  is  1  inch. 
In  the  4-inch  beam  (C)  the  distance  is  2  inches,  etc. 

SECTION  MODULUS. 

For  the  purpose  of  readily  calculating  beams  and  for  com- 
paring one  with  another,  the  want  of  some  coefficient  or  constant 
was  felt,  whereby  one  section  could  be  compared  directly  with 
another  section  without  previous  calculation.  When  one  beam  is 
to  be  compared  with  another,  as  shown  above,  it  is  necessary  to 
multiply  the  width  by  the  cube  of  the  depth,  a  very  unhandy 
method.  But  the  moments  of  inertia  may  be  compared  if  they  are 
divided  by  the  distance  from  neutral  axis  to  the  furthest  fiber,  thus 
forming  a  very  convenient  method  of  making  the  necessary  cal- 
culations for  finding  the  strength  of  various  shaped  beams  or  for 
ascertaining  the  proper  size  of  beam  for  a  given  load. 

Some  name  had  to  be  given  to  the  new  characteristic  of  beam 
sections,  and  it  chanced  to  be  called  the  "section  modulus"  which 
is  perhaps  as  good  a  name  as  any  and  a  much  better  one  than 
"moment  of  inertia."  It  depends  entirely  upon  the  size  and  shape 
of  the  section  and  is  independent  of  the  material,  length,  or  load 
of  the  span. 


170  MILLWRIGHTING 

If  the  moment  of  inertia  be  divided  by  the  distance  of  the 
farthest  fiber  the  result  will  be  the  "section  modulus,"  and  if  the 
section  modulus  be  multiplied  by  the  stress  permitted  in  the 
extreme  fibers  the  result  will  be  the  resisting  moment  of  the  beam 
or  lever.  As  the  resisting  moment  always  equals  the  bending 
moment  (unless  the  beam  breaks)  then  the  section  modulus  can 
be  readily  found  by  simply  dividing  the  bending  moment  by  the 
fiber  stress.  Or,  by  multiplying  the  section  modulus  by  the  fiber 
stress,  the  bending  moment  is  found. 

THE  BENDING  MOMENT. 

Referring  again  to  Fig.  71,  the  load  c,  applied  to  the  rod,  if 
multiplied  by  one-fourth  the  distance  between  c  and  d,  will  be  the 
the  bending  moment.  If  the  load  is  applied  at  one  end,  as  in  the 
case  of  a  lever,  then  the  bending  moment  will  be  the  load  multiplied 
by  the  length.  If  the  beam  is  in  a  floor  where  it  is  uniformly 
loaded,  the  bending  moment  is  one-eighth  of  the  load  times  the 
leverage,  or  distance  between  supports.  Thus,  if  a  channel-iron 
or  I-beam  is  to  be  used,  the  bending  moment  may  be  divided  by 
the  fiber  stress  permitted — 12,000  to  15,000 — and  the  section 
modulus  is  obtained  from  which  the  size  and  shape  of  the  beam 
most  convenient  may  be  directly  taken,  and  a  choice  may  be  had 
of  any  structural  shape  listed  in  the  maker's  catalog. 

If  wood  is  to  be  used  for  the  beam  or  lever,  divide  the  bend- 
ing moment  by  the  stress  permissible  in  the  fiber,  and  the  section 
modulus  is  obtained  of  a  section  which  will  do  the  work.  But 
the  moment  of  inertia  and  section  modulus  are  more  frequently 
used  for  structural  shapes,  although  wooden  beams  are  also  cal- 
culated in  that  manner,  particularly  in  machine  design,  for  levers, 
frames  of  machines,  and  for  similar  work. 

CALCULATING  A  BEAM  FOR  GIVEN  WORK  OR  LOAD. 

Should  the  millwright  find  need  for  timbers  to  support  a 
machine  weighing  10,000  pounds,  as  shown  by  Fig.  73,  the  dis- 
tance between  supports  being  15  feet,  what  width  and  depth  of  tim- 
bers would  be  required?  The  conditions  in  this  case  are  those  of  a 
beam  supported  at  both  ends  and  loaded  in  the  middle.  As  there 
are  to  be  two  timbers  or  beams,  the  load  on  each  will  be  5000 
pounds.  Multiplying  the  distance  between  supports  by  the  load, 


STRENGTH  OF  MATERIALS  171 

and  dividing  by  4,  gives  5000X15^4=18,750,  the  bending 
moment  of  the  beam.  But  this  quantity  is  in  foot-pounds,  and  we 
desire  it  in  inch-pounds,  hence  it  is  necessary  to  multiply  by  12: 
18,750X12=225,000  inch-pounds.  To  obtain  the  section  modulus 
of  a  timber  which  would  safely  carry  the  load,  it  is  only  neces- 
sary to  divide  225,000  by  the  safe  fiber  stress  of  the  material  from 


FIG.  73.— CALCULATING  A  BEAM  TO  CARRY  A  GIVEN  LOAD. 

which  the  beam  is  to  be  made.  As  different  materials  have  differ- 
ent strengths,  it  is  necessary  for  the  millwright  to  be  provided  with 
a  table  giving  the  strengths  of  various  materials,  wood,  steel,  etc. 
The  values  of  steel  sections  may  be  obtained  from  the  pocket- 
books  issued  by  any  of  the  steel  manufacturers,  one  or  more  of 
which  books  should  be  in  the  possession  of  the  millwright. 

BREAKING  STRENGTH  OF  TIMBER. 

The  strength  of  wood  is  also  given  in  the  books  in  question, 
also  in  Trautwine,  of  which  every  millwright  should  have  a  copy. 
A  brief  table  of  average  "moduli  of  rupture"  is  given  below. 
This  quality  is  the  unit  stress  observed  when  the  timber  was 
broken  in  a  testing  machine,  and  it  is  a  more  convenient  form 
to  use  than  the  ultimate  strength  of  the  material. 

Taking  the  extreme  fiber  stress  as  one-fifth  the  amount  given 
in  the  table,  for  spruce  the  fiber  stress  would  be  1000,  while  for 
yellow  pine  it  would  be  2500  pounds  to  the  square  inch.  It  will 
be  assumed  that  yellow  pine  is  to  be  used  for  the  timbers  and 
we  divide  the  inch-pounds  by  the  extreme  fiber  stress  and 


172 


MILL  WEIGHTING 


obtain  225,000-f-2500X90,  which  is  the  section  modulus  of  the 
timber  required  to  carry  the  load. 

From  tables  of  beams,  and  in  a  previous  paragraph,  it  is 
found  that  the  section  modulus  of  a  rectangle,  like  C,  Fig.  72, 
is  one-sixth  of  the  width  times  the  square  of  the  depth  of  the 

TABLE  III.— MODULI  OF  RUPTURE. 


Timber. 

Average. 

Spruce                

5,000 

Hemlock 

4  500 

\Vhite  pine 

8  000 

Lonp'-leaf  (yellow)  pine  . 

12,000 

Short-l°af  pine 

10  000 

Douglas  spruce 

8  000 

White  oak                              

13,000 

Red  oak  

11,500 

beam.  Or,  the  breadth  times  square  of  the  depth=90X  6=540. 
We  may  now  find  the  depth  by  assuming  a  width  and  calcu- 
lating the  depth  required  by  that  width,  as,  by  once  having  found 
the  section  modulus,  we  can  find  any  number  of  sections  of  beam 
which  will  have  the  same  strength.  We  can  also  use  the  section 
modulus  in  substituting  steel  beams,  as  will  be  determined  later. 

CALCULATING  A  BEAM. 

Assuming  that  the  beam  is  to  be  6  inches  wide,  the  depth  will 
be  the  square  root  of  540-=-6=90,  and  as  the  square  root  of 
90  is  nearly  9%,  it  will  be  seen  that  6x9-inch  timber  is  not 
quite  large  enough;  6xlO-inch  should  therefore  be  selected  for 
the  work.  But  supposing  that  a  timber  8  inches  wide  be  selected. 
Then  the  depth  will  be  540-^8=67i/_>,  and  the  square  root  of 
this  is  about  814  inches.  An  8x8-inch  would  be  a  little  small, 
but  it  would  not  change  the  factor  of  safety  greatly,  so  either 
could  be  used  as  the  sizes  chanced  to  be  on  hand.  The  8x8  inch 
timber  has  a  section  of  64  square  inches,  and  the  6xlO-inch  has 
an  area  of  60  square  inches,  therefore  it  is  cheaper  as  far  as 
lumber  is  concerned  to  use  the  latter  size. 

For  observation,  calculate  the  depth  required  were  a  4-inch 
timber  used :  540-^-4=135,  and  the  square  root  of  this  is  11.6 
inches  nearly,  showing  that  a  4xl2-inch  timber  would  carry  the 
load  as  well  as  a  6xlO-inch.  Even  if  nothing  was  at  hand  but 


STRENGTH  OF  MATERIALS  173 

2-inch  plank,  the  millwright  could  put  in:  540-^-2=270,  the 
square  root  of  which  is  about  16%  inches  in  depth  for  the  timber. 
This  would  need  staying  sidewise,  but  it  would  carry  the  load 
and  it  would  only  call  for  33  square  inches  of  lumber  section. 
In  this  manner  the  millwright  can,  by  using  the  section  modulus, 
take  his  choice  of  several  timber  sections  to  do  the  work  accept- 
ably and  at  the  same  time  appear  as  good-looking  as  possible  when 
executed. 

Should  it  be  required  to  use  structural  steel  instead  of  wood, 
the  same  bending  moment  is  used,  viz:  225,000,  but  a  fiber 
stress  of  15,000  will  be  allowed  for  steel,  giving  a  quotient  of  15. 
Multiplying  this  by  6,  as  before,  gives  90  as  the  width  and  square 
of  depth  product.  But  the  width  and  breadth  business  will  not 
work  with  steel,  and  we  must  get  out  our  steel  handbooks  and 
look  up  the  section  modulus  of  the  shape  it  has  been  decided  to 
use.  Here  we  find  that  even  the  multiplying  by  6  is  not  needed, 
and  that  by  looking  up  under  I-beams  the  one  having  a  section 
modulus  of  15,  we  find  that  an  8-inch  beam  weighing  20% 
pounds  to  the  foot  will  fill  the  bill. 

If  we  wish  to  put  in  channels  instead  of  I-beams  look  for 
the  one  which  has  a  section  modulus  of  15,  and  it  is  found  to  be  a 
10-inch,  weighing  20  pounds  to  the  foot.  Truly  the  understand- 
ing and  use  of  the  section  modulus  and  the  moment  of  inertia 
will  be  a  great  help  to  the  millwright  who  has  machine  settings 
to  rig  up.  In  the  above  problem  it  is  understood  that  two  simi- 
lar beams  or  timbers  will  be  required,  as  the  figuring  was  done 
for  only  one-half  the  load  of  10,000  pounds. 

CRUSHING  STRENGTH  AND  COMPRESSION. 
The  crushing  strength  of  material  is  very  easy  to  handle  or  to 
calculate.  It  is  given  directly  in  pounds  to  the  square  inch  or 
square  foot,  and  it  is  only  a  question  of  enough  area  to  carry 
the  given  load.  Wood  will  usually  carry  about  800  pounds  to 
the  square  inch  on  side  grain  before  crushing,  and  in  putting  up 
frames  for  machines  and  for  buildings,  the  millwright  should  see 
that  all  pieces  have  enough  surface  bearing  to  carry  the  load  with 
a  fair  factor  of  safety.  In  Fig.  73,  the  timbers  which  carry  load  a 
must  at  each  end  transfer  to  the  foundation  timbers  at  least  2500 
pounds  besides  their  own  weight.  To  give  the  bearing  surface  a  fac- 


174 


MILLWRIGHTING 


tor  of  safety  of  five  will  require  that  the  surfaces  are  not  loaded 
more  than  stated  by  the  following  table  of  "limiting  unit  stresses" 
compiled  from  a  bridge  specification  for  combination  bridges  by 
The  Baltimore  &  Ohio  Railroad  Company. 


LIMITING  UNIT   STRESSES. 


Timber. 
Pounds  to  the  square 
inch. 

Yellow 
Pine. 

White 
Pine. 

White 
Oak. 

Bearing,  with 
grain 

1500 

1000 

1200 

Bearing,  cross 
grain  

350 

200 

500 

By  this  table,  the  timber-bearing  surface  at  each  end  should 
be  2500-^350=7.14  square  inches  on  yellow  pine,  2500-^200=12.5 
on  white  pine,  and  2500^500=5  inches  on  oak.  Should  4x12- 
inch  timbers  have  been  used,  it  would  be  necessary  that  they 
project  across  the  bearing  timbers  at  least  2  inches  for  the  yellow 
pine,  3  inches  for  white  pine,  and  l1/^  inches  for  oak.  The  mill- 
wright should  watch  this  point  very  carefully  when  placing 
machinery  loads  on  wooden  bearings  or  blocking. 

The  loads  necessary  to  crush  a  bearing  surface,  across  the 
grain,  to  a  depth  of  1/10  of  an  inch,  are,  according  to  Watertown 
tests  for  the  U.  S.  Government,  2600  pounds  for  Georgia  pine, 
1200  pounds  for  white  pine,  and  4000  pounds  for  oak.  Spruce 
will  stand  about  as  much  as  white  pine.  When  it  is  necessary 
to  put  wood  into  shaft  friction  clutches,  it  is  well  to  keep  these 
figures  in  mind  and  to  figure  what  load  is  coming  upon  the 
wood  while  the  clutch  is  working. 

BEARING  POWER  OF  BOLTS  AND  DAPS. 

When  two  timbers  are  bolted  together,  the  same  thing  conies 
up.  Washers  bearing  upon  side  wood  must  not  be  loaded  to 
more  than  the  figures  given  will  allow.  Bolts,  too,  are  frequently 
so  arranged  that  they  are  dragged  into  the  wood  by  a  load  which 
should  have  been  carried  otherwise.  Fig.  74  shows  several 
examples  of  good  and  bad  bolt  arrangement.  At  a  a  timber  is 
shown  held  to  post  e  by  nothing  except  the  pressure  between 
the  timbers  and  the  carrying  power  of  the  bolt  upon  the  wood,  in 
post  and  in  timber.  This  is  a  very  bad  arrangement  as  will  be 
shown  later. 


STRENGTH  OF  MATERIALS 


175 


The  arrangement  shown  at  b  is  properly  arranged.  The  load 
which  may  be  safely  placed  on  this  timber  without  danger  of 
crushing  the  side  fibers  is,  for  an  8x8-inch  timber  with  a  dap 
1  inch  deep,  white  pine  bearing  on  a  yellow  pine  post,  8X200= 
1600  pounds — and  it  should  not  be  loaded  greater  than  that 
amount  if  for  machinery-supporting  timbers.  But  something 
may  be  gained  by  using  different  kinds  of  wood.  Let  a  stick  of 
yellow  pine  be  placed  at  b,  and  a  white  pine  post  used  instead  of 


FIG.    74.— BEARING  POWER   OF   SIDE-WOOD   ON   BOLTS   AND   "DAPS." 

the  arrangement  noted  above.  Then  the  yellow  pine  beam  can 
stand  8X350=2800  pounds,  instead  of  1600.  The  pine  wood  in 
the  post  must  carry  the  same  load  it  did  before,  but  the  strain 
comes  on  the  end  grain  of  that  wood  which,  by  the  table,  can  carry 
a  load  of  1000  pounds  on  its  end  grain,  while  it  will  stand  for  only 
200  pounds  on  side  grain.  Thus,  the  load  on  the  post  comes  upon 
end  wood  and  can,  therefore,  carry  many  times  the  load  required 
of  it. 

When  the  dap  is  omitted,  and  the  piece  of  scantling  or  plank 
is  placed  as  shown  at  c,  Fig.  74,  the  safe  load  to  be  placed  upon 


176 


MILLWRIGHTING 


that  form  of  construction  is,  supposing  a  2x8-inch  scantling  to 
have  been  used,  8X2X350=5600  pounds.  Even  for  a  white 
pine  beam  at  c  the  safe  carrying  power  would  be  2X8X200= 
3200  pounds.  When  extra  strength  is  necessary,  the  dap  can  be 
reinforced  with  the  scantling,  and  the  carrying  power  of  the  con- 
nection be  increased  to  the  sum  of  the  loads  found  for  b  and  c, 
amounting  to  4800  pounds  for  white  pine  and  8400  pounds  for 
the  yellow  pine.  In  this  manner  a  post  and  beam  connection  may 
be  made  to  carry  almost  any  load.  Certainly  such  an  arrange- 
ment will  carry  any  stress  likely  to  be  met  with  in  machinery 
setting. 

EFFECT  OF  SIDE  OVERLOAD  ON  BOLTS. 

As  noted  above,  the  connection  at  a,  Fig.  74,  is  a  very  poor 
one  when  much  load  is  to  be  carried — particularly  when  a  live 
load  like  that  of  moving  machinery  is  to  be  sustained.  The  effect 
of  such  a  bolt  connection  is  shown  by  Fig.  75,  a  sectional  view 
of  the  same  lettering  in  the  preceding  engraving.  The  beam  a 
was  originally  located  at  b,  and  has  set- 
tled to  the  position  in  which  it  is  shown. 
To  sustain  the  load,  aside  from  the 
friction  between  a  and  c,  which  is  negli- 
gible as  the  bolt  gets  loose,  there  is 
nothing  but  the  bearing  of  the  bolt 
against  the  wood  surfaces.  It  will  be 
noted  that  the  bolt  is  out  of  place  more 
in  a  than  in  c.  This  is  because  the  bear- 
ing of  the  bolt  in  a  is  on  side  wood  which 
crushes  much  easier  than  does  the  end 
wood  against  which  the  bolt  bears  in 
post  c. 

When  the  timber  first  commenced  to 

settle,  the  bolt  bore  only  across  the  extreme  corner  of  the  wood. 
After  a  little  pressure  had  been  exerted,  the  bolt  obtained  a 
bearing  of  about  1  inch  of  its  length,  which  held  until  the  load 
crushed  the  few  fibers  bearing  against  the  bolt.  Then  the  set- 
tling of  the  beam  a  continued  until  the  bolt  was  bent  down  as 
shown,  and  the  fibers  had  crushed  until  a  sufficient  number  of 
inches  of  bearing  had  been  obtained  to  carry  the  load. 


FIG.    75.— EFFECT    OF 
BOLT    OVERLOAD. 


STRENGTH  OF  MATERIALS 


177 


The  millwright  here  has  an  excellent  opportunity  to  study 
the  reason — or  one  reason — why  framing  put  up  in  this  manner 
is  so  long  in  coming  to  its  bearings,  why  it  settles  continually, 
and  never  seems  to  reach  a  place  where  it  can  stay  put.  The 
reason  is  easily  found.  It  is  in  the  continuous  settling  of  the 
fibers  against  which  the  bolt  bears  in  a  and  c.  Such  construc- 
tion can  never  be  made  to  stay  in  place,  and  shafting  placed 
upon  such  framing  will  be  continually  getting  out  of  level  and 
alinement,  no  matter  how  often  it  is  put  in  place.  Use  the  dap 
or  slab  methods,  as  shown  by  c  and  d  Fig.  74,  and  the  shafting 
will  always  stay  where  you  left  it. 

BEARING  PLATES. 

When  it  is  necessary  to  make  a  timber  carry  a  heavy  load 
with  but  little  area  of  bearing  upon  its  supports,  then  the  same 


FIG.  76.-BEARING  PLATES. 


method  must  be  employed  as  when  heavy  weights  must  be  sup- 
ported upon  soft  ground.     In  that  case  a  foundation  was  pre- 


178  MILLWRIGHTING 

pared  which  distributed  the  load  over  the  amount  of  soft  soil 
necessary  to  carry  that  load.  Exactly  the  same  thing  must  be 
done  by  the  millwright  when  he  must  place  more  than  a  crushing 
load  upon  a  side  of  a  timber. 

As  shown  by  Fig.  76,  a  metal  plate  must  be  interposed  between 
the  two  wooden  surfaces  to  distribute  the  load  over  the  area 
necessary  to  carry  it.  The  same  thing  is  done  when  a  washer  is 
placed  under  a  nut  which  is  to  be  screwed  down  upon  -a  wood  sur- 
face. At  a,  Fig.  76,  is  shown  a  beam  or  joist  with  a  very  slight 
bearing  on  timber  c,  the  surfaces  in  contact  being  far  too  small 
to  carry  the  load  to  the  square  inch  which  must  come  upon  them. 
The  solution  of  this  problem  is  to  calculate  the  number  of  inches 
of  area  necessary  between  a  and  e,  then  form  the  metal  plate  d 
to  have  the  required  bearing  surface  upon  timber  c.  To  prevent 
the  fibers  in  a  from  being  crushed,  simply  extend  the  plate  under- 
neath a  to  a  distance  which  secures  the  area  of  contact  needed, 
then  hang  up  the  far  end  of  of  by  means  of  a  U-bolt  or  some  other 
adequate  device. 

The  problem  is  an  easier  one  when  end  wood  is  to  be  pre- 
sented to  timber  e  as  at  b,  where  the  load  upon  post  b  is  great 
enough  to  crush  in  c,  but  will  not  injure  the  end  wood  in  b.  In 
this  case  it  is  necessary  merely  to  calculate  the  area  of  a  plate 
large  enough  to  protect  e,  then  set  post  b  on  top  of  that  plate  c, 
and  nothing  further  is  required. 

TIMBER-CRUSHING  JOURNAL  BEARINGS. 

Trouble  is  sometimes  met  with  in  some  bearings  which  per- 
sist in  cutting  deeply  into  the  timbers  upon  which  they  rest. 
When  this  is  met  with,  investigate  the  bearings  and  see  if  they  are 
not  like  that  shown  by  Fig.  77,  with  a  narrow  rim  around  the 
lower  edge  as  shown  at  a  and  b.  Journal  boxes  made  in  this 
manner  were  originally  intended  to  be  bolted  to  steel  beams  or 
to  other  metal  parts.  They  were  never  intended  to  be  attached 
to  wood.  But  the  machine  manufacturer,  finding  that  these  bear- 
ings are  considerably  cheaper  than  the  solid  foot  variety,  sends 
them  out  for  wood  as  well  as  for  iron  construction,  hence  the 
trouble  of  their  cutting  into  the  timbers,  as  described. 

When  bearings  of  this  kind  are  met  with,  three  courses  are 
open:  The  bearing  may  be  turned  upside  down  and  the  space 


STRENGTH  OF  MATERIALS  179 

filled  with  a  piece  of  wood  laboriously  fitted  in  to  the  corners 
and  rough  places.  That  is  one  way.  Another  is  to  fill  the  cavity 
full  of  babbitt  metal — a  sure  way,  but  a  costly  one.  A  variation  of 
this  way  is  to  fill  the  cavity  with  pieces  of  wire,  nails,  and  other 
small  bits  of  scrap,  then  pour  in  thin  cement  or  melted  brimstone, 


FIG.    77.— A   BEARING  WHICH   CRUSHED    INTO   THE   TIMBER. 

strike  the  top  off  level  and  let  stand  until  set,  then  bolt  the  bear- 
ing in  place  with  the  cement  smoothly  fitting  to  the  woodwork. 
The  third  method  is  to  place  a  plate  of  iron  under  the  bearing — 
a  modification  of  the  plate  method,  Fig.  76 — and  then  bolt  the 
bearing  fast  upon  the  plate  in  question.  The  cement  method  is 
preferable  and  leaves  little  to  be  desired — except  a  better  box- 
foot  to  begin  with. 

SHEARING  STRENGTH  OF  TIMBER. 

One  more  property  of  timber — and  of  steel  as  well — the  mill- 
wright should  thoroughly  understand  and  that  is,  the  strength 
of  wood  and  of  steel  as  regards  shearing.  About  every  operation 
in  wood  and  in  iron  working  (by  cutting)  is  done  by  shearing 
off  some  of  the  material.  The  chisel  acts  by  shearing,  the  drill 
shears  up  some  of  the  metal,  and  the  bit  bores  wood  by  shear- 
ing off  a  chip  of  uniform  thickness. 

A  boiler  often  fails  by  some  of  the  rivets  shearing  off,  and  in 
a  timber  truss,  as  well  as  in  every  beam,  shear  is  the  most  com- 
mon manner  of  failure.  Lumber  seldom  or  ever  fails  by  shearing 
across  the  grain.  A  break  in  that  direction  is  usually  a  break 
due  to  tensile  strain.  When  a  pin  fails  in  a  mortise,  it  is  usually 
the  case  that  the  tenon  shears,  a  piece  being  pulled  out  of  it. 
Should  the  pin  be  torn  off,  the  break  would  be  shear,  pure  and 
simple,  and  if  the  pin  broke  twice,  once  on  either  side  of  the 


180  MILLWRIGHTING 

tenon,  it  would  be  said  to  have  been  in  double  shear.  The  same 
is  the  case  with  rivets,  whether  in  tin  or  in  steam  boiler,  and 
when  they  are  in  double  shear  they  have  double  the  resistance 
that  they  have  in  single  shear. 

Wood  fails  in  shear  almost  entirely  with  the  grain.  It  splits 
or  slides  off  through  endwise  pressure,  as  shown  by  Fig.  78, 
which  represents  a  portion  of  the  foot  of  a  truss.  When  a 


FIG.    78.— SHEARING   STRENGTH    OF   TIMBER. 

framed  timber  of  this  kind  fails  it  does  so  by  shearing  off  the 
wood  along  the  lines  abed,  pressure  being  exerted  in  the 
direction  P.  The  force  necessary  to  strip  off  the  wood  above 
the  dotted  lines  is  not  affected  by  the  thickness  of  the  wood  above 
that  line,  but  depends  entirely  upon  the  kind  of  wood  and  the 
length  and  breadth  of  the  piece  to  be  sheared  off.  The  following 
table  gives  the  strength  in  shear  of  the  principal  woods  used 
in  millwrighting : 

SHEARING  STRENGTH  OF  TIMBER 

Hemlock 300  pounds  to  the  square  inch. 

White  pine    400      "         "     " 

Yellow  pine   (long  leaf)   850      "         "     " 
Yellow  pine  (short  leaf)   775      "         "     " 

Douglas  spruce    500      "         "     " 

White  oak  1000      "         "     " 

Red  oak  1100      "         "     " 

The  shearing  strength  of  wood  across  the  grain  is 
probably  four  to  six  times  the  amounts  given  above, 
but  wood  seldom  fails  by  shearing  in  that  direction. 


STRENGTH  OF  MATERIALS 


181 


Were  the  timber  shown  by  Fig.  78  made  of  white  pine,  and 
the  section  abed  exactly  one  inch  square,  it  would  require  400 
pounds  applied  at  P  to  split  the  timber  along  the  dotted  lines. 
Were  the  space  abed  one  inch  wide  and  two  inches  long,  or 
two  inches  wide  and  one  inch  long,  the  power  required  to  do  the 
shearing  would  be  800  pounds,  showing  that  the  resistance  of  the 
wood  is  exactly  according  to  the  area  to  be  sheared.  Thus,  were 
the  space  abed  10x10  inches,  it  would  require  40,000  pounds 
pressure  at  P  to  shear  off  the  material  above  the  dotted  lines. 

HOLDING  POWER  OF  JOINT-BOLTS. 

The  holding  power  of  any  joint-bolt  is  calculated  by  combi- 
ning the  compression  and  shear  strains  as  above  laid  down.  Joint- 
bolts  are  a  nuisance  to  begin  with,  and  they  should  never  be  used 
when  there  is  any  way  of  getting  rid  of  them.  The  usual  joint- 
bolt  is  much  like  any  bolt  except  the  end  is  pointed  to  enter  the 
nut  easily,  and  the  nut  is  usually  made  square  to  prevent  its  turn- 
ing around  in  the  mortise.  The  hole  is  bored  I/Q  inch  larger  than 


FIG.    79.— HOLDING   POWER   OF   JOINT-BOLTS. 

the  rod  for  joint-bolts  (holes  for  ordinary  bolts  are  usually  bored 
1/16  inch  larger  than  the  rod  or  body  of  the  bolt  for  sizes  below 
1  inch,  and  %  inch  larger  for  sizes  greater  than  1  inch  in  diam- 
eter) in  order  that  the  bolt,  possibly  a  little  crooked,  may  be 
turned  around  in  the  hole  and  nut. 

As  arranged  in  Fig.  79,  the  joint-bolt  c  is  slipped  into  the 
hole  g,  bored  as  above  described  to  receive  the  rod  or  shank  of 
the  bolt.  Hole,  g  is  intercepted  by  the  mortise  d,  which  has  been 
beaten  in  the  inside  of  timber  b;  and  the  distance  e,  from  the 


182 


MlLLWRIGHTING 


mortise  to  the  end  of  timber  b,  must  be  considered.  A  cut  washer 
should  be  placed  under  the  nut,  and  it  is  usual  to  place  a  cast 
washer  under  the  head,  as  that  end  of  the  bolt,  bearing-  on  side 
wood,  needs  a  larger  bearing  surface  than  does  the  nut  which 
bears  against  end  wood. 

Considering  the  joint-bolt  c,  Fig.  79,  to  be  %  inch  in  diameter, 
what  sizes  of  washers  are  necessary  to  hold  this  bolt  in  a  white 
pine  frame  with  8x8-inch  posts  and  6x8-inch  girts  ?  The  general 
arrangement  may  be  as  shown  by  Fig.  79,  the  bolt  being  placed 
in  the  middle  of  post  a,  the  mortise  and  tenon  being  merely  to 
prevent  lateral  movement  of  timber  b  during  erection  and  while 
the  bolt  is  loose.  Thus  the  bolt  is  brought  close  to  the  inside  of 
beam  bf  so  the  mortise  need  not  be  of  great  depth  to  receive  the 
nut  and  washer.  The  washer  to  go  over  a  %-inch  bolt  must  have 
a  diameter  of  15/16  inches,  and  as  shown  by  the  following  table 
such  a  washer  has  a  diameter  of  214  inches.  For  convenience, 
the  following  table  of  cut  washers  is  presented. 

CUT   WASHERS. 

Diameters    given    in    inches  ;    Thickness   in   Birmingham 
wire  gage  ;    Number  of   washers  to  the  pound. 


Diameters  in 
Inches. 

Thickness, 
B.w.g. 

Number  in 
One  Pound. 

} 

1 

18 

450 

| 

ft 

16 

210 

A 

16 

139 

| 

1 

16 

112 

1 

A 

14 

68 

11 

14 

43 

n 

ft 

12 

26 

li 

12 

22.5 

l! 

M 

10 

13.1 

2 

1| 

10 

10.1 

21 

fl 

9 

8.6 

2£ 

1A 

9 

6.2 

2f 

H 

9 

5.2 

3 

if 

9 

4 

3} 

n 

9 

2.8 

The  bolt  c,  Fig.  79,  being  fitted  with  a  washer  2^4  inches  in 
diameter,  and  the  bolt  hole  being  1  inch  in  diameter,  the  bearing 
of  the  nut  will  be  upon  the  area  of  end  wood  contained  between 
the  two  circles  mentioned.  These  areas  may  be  calculated,  but 
it  is  better  to  take  them  directly  from  a  table  of  circles  which  is 
to  be  found  in  every  handbook.  Thus  found,  the  areas  are  3.97 


STRENGTH  OF  MATERIALS  183 

and  0.7854.  Taking  one  from  the  other,  there  is  an  area  of  3.18 
square  inches  to  withstand  the  strain  of  the  bolt  which  is  limited 
to  5000  pounds;  or  5000-^3.18=1572  pounds  to  the  square  inch. 
From  the  table  of  crushing  strength  of  wood  it  is  found  that 
white  pine  will  crush  its  end  fibers  under  a  load  of  1000  pounds 
to  the  square  inch.  There  is,  then,  power  enough  in  the  screwing 
up  of  the  bolt  to  crush  the  wood  under  the  washer,  and  the  design 
is  not  a  good  one.  Some  other  wood  should  be  used  for  the  girts, 
or  else  a  larger  washer  should  be  made  and  used.  For  cases  of 
this  kind,  it  is  sometimes  the  fashion  to  cut  off  pieces  of  flat  iron 
.which  will  just  pass  easily  into  the  mortises.  These  pieces 
are  drilled  and  tapped  and  used  as  nuts  for  the  joint-bolts.  Were 
this  to  be  done  in  the  case  above  noted,  there  would  be  secured 
21/2X4=10  square  inches  of  bearing  surface,  or  about  9.21 
square  inches  after  the  area  of  bolt  hole  has  been  deducted,  leav- 
ing 9.21  square  inches  of  bearing  surface,  equal  to  5000-f-9.21 
=542  pounds  to  the  square  inch,  thus  giving  a  factor  of  safety 
of  about  2. 

RESISTANCE  TO  SHEARING. 

Another  point  which  would  be  investigated  is  the  possibility 
of  pulling  the  cut  washer  through  the  end  of  girt  b,  Fig.  79. 
The  circumference  of  the  214-inch  washer  above  mentioned  is 
(taken  from  the  table  of  circles)  7.07  inches,  and  the  shearing 
strength  of  pine  wood  being  400  pounds  to  the  square  inch,  each 
inch  length  of  timber  in  e  would  carry  400X7.07=2830  pounds. 
Hence,  to  just  carry  the  load,  there  should  be  5000-^2830=1.77 
inches  of  wood.  But  there  is  no  factor  of  safety  in  this,  and  to 
provide  a  factor  of  safety  of  2  (about  the  same  as  for  the  crush- 
ing strain  in  the  preceding  paragraph)  there  should  be  2X1-77 
=3.54  inches  of  wood.  Therefore,  the  distance  e  should  not  be 
less  than  3l/2  inches. 

We  have  not  yet  investigated  the  bearing  of  the  washer  on  the 
outside  of  post  af  Fig.  79.  Sometimes  cut  washers  are  used 
at  this  point,  again  cast  washers  are  used  as  occasion  requires. 
With  a  cut  washer,  the  strain  will  be  the  same  as  for  the  nut  end 
of  the  bolt,  or  1572  pounds  to  the  square  inch.  Here  is  trouble : 
Pine  wood  will  crush  under  a  load  of  200  pounds  to  the  square 
inch  across  the  grain,  heVice  to  carry  5000  pounds  there  should 


184 


MILLWRIGHTING 


be  5000-1-200=12%  square  inches.  And  with  a  factor  of  safety 
of  2,  there  would  have  to  be  25  square  inches  to  make  this  part 
of  the  work  as  strong  as  the  rest.  This  means  a  washer  nearly 
5%  inches  in  diameter. 

It  looks  as  if  it  would  be  better  to  use  some  other  kind  of 
wood  for  the  posts  of  this  frame.  As  yellow  pine  stands  350 
pounds  side-grain  pressure,  and  oak  is  good  for  500  pounds, 
the  size  of  the  washer  necessary  to  carry  the  strain  of  a  %-inch 
bolt  on  the  latter  wood  may  be  reduced  to  254  or  2y2  inches. 
If  the  yellow  pine  timber  is  used,  the  washer  should  be  3.63 
inches  in  diameter,  or  about  3%  inches.  Thus  it  is  found  that  the 
cut  washer  2%  inches  in  diameter  is  still  too  small,  even  with 
oak  posts,  and  it  is  in  order  to  use  cast-iron  washers  of  larger 
diameter. 

The  following  table  of  cast-iron  washers  was  furnished  by 
The  Fairbanks  Company,  and  the  list  has  proven  satisfactory 
during  several  years'  use : 

CAST  WASHERS. 


Diameters  and  Thickness  in  Inches. 

Size  of 
Bolt. 

Weight  in 
Pounds. 

Washer. 

Hole. 

Thickness. 

2i 

f 

ft 

i 

£ 

2f 

3. 
4 

t 

f 

f 

3 

1 

ft 

|^ 

| 

3* 

1 

| 

H 

4 

H 

if 

1 

If 

4* 

H 

i 

i* 

21 

5 

if 

U 

it 

3 

6 

l| 

i  \ 

!i 

5 

The  table  shows  that  a  cast  washer  for  a  %-inch  bolt  has  an 
outside  diameter  of  3^  inches,  with  a  hole  1  inch  in  diameter 
through  it.  This  leaves  6.9211—0.7854=8.83  square  inches  of 
bearing  surface  to  carry  a  load  of  5000  pounds,  or  866  pounds  to 
the  square  inch.  Hence  even  with  a  cast  washer  on  an  oak  post, 
there  would  be  too  much  pressure  to  the  square  inch.  If  so  large 
a  bolt  must  be  used,  a  5-inch  washer  must  be  made  and  used  as 
noted  above,  but  there  may  not  be  any  need  of  so  much  holding 
power,  especially  as  the  timbers  are  only  8x8  inches,  and  6x8 
inches. 

A  %-inch  bolt  would  probably  do  all  that  is  required,  or  pos- 
sibly a  %-  or  even  a  %-inch  affair  might  give  the  necessary 


STRENGTH  OF  MATERIALS 


185 


clamping  power.  The  above  calculations  are  given,  not  because 
there  might  be  need  of  a  %-inch  bolt  in  the  small  frame 
described,  but  to  make  clear  to  the  millwright  the  necessity  for  so 
designing  the  several  parts  of  the  work  he  is  doing  that  there 
will  neither  be  a  weak  spot  in  one  place  or  a  useless  expenditure 
of  material  in  another  part  of  the  work.  With  a  little  thought 
in  the  lines  indicated  above,  the  stresses  in  compression  and  in 
shear,  as  well  as  those  of  tension  and  transverse  loads  may  be 
easily  determined  and  met  by  suitable  material  rightly  placed. 
This  is  where  the  "materials  and  forces  of  nature"  come  into  play, 
as  described  in  the  first  chapter. 

STRENGTH  OF  IRONWORK. 

The  strength  of  ironwork  is  calculated  in  much  the  same 
manner  that  woodwork  is  figured.  Of  the  two,  ironwork  is  the 
easier  to  handle,  for  the  material  is  more  uniform  in  strength, 
more  condensed,  and  lends  itself  easier  to  the  necessary  calcula- 
tions. The  matter  of  bolts  is  pretty  well  covered  in  the  para- 
graphs above,  though  a  table  of  the  safe  loads  of  bolts  is  very 
handy  and  saves  much  time,  and  such  a  table,  as  prepared  by  the 
writer  for  his  own  use,  is  given  herewith.  This  table  is  calculated 
for  a  tensile  strength  of  60,000  pounds  to  the  square  inch,  United 
States  Standard  thread,  with  a  factor  of  safety  of  5  based  upon 
the  diameter  of  the  bolt  at  the  bottom  of  the  thread. 

DIAMETER,  PITCH  AND  STRENGTH  OF  BOLTS. 


Diameter 
in 
Inches 

Diameter  at 
Bottom 
of  Thread 

Threads 
to  the 
Inch. 

Safe 
Load  in 
Pounds. 

| 

0.185 

20 

323 

TS 

0.240 

18 

542 

0.294 

16 

737 

~  Iff 

0.344 

14 

1,118 

0.400 

13 

1,515 

& 

0.454 

12 

1,940 

$ 

0.507 

11 

2,424 

| 

0.620 

10 

3,645 

| 

0.731 

9 

5,010 

1 

0.837 

8 

6,610 

11 

0.940 

7 

8,350 

-    H 

1.065 

7 

10,100 

Bolts  usually  fail  by  breaking  in  the  thread,  and  when  great 
strength  is  required,  the  ends  of  the  bolts  are  upset  until  the 
diameter  at  the  bottom  of  the  thread  is  the  same  as  the  diameter 


186 


MILLWRIGHTING 


of  the  body  of  the  bolt.  But  this  treatment  does  not  give  full 
strength,  for  upsetting  does  weaken  the  metal,  and  many  tests  of 
bolts  in  a  machine  have  demonstrated  that  bolts  upset  until  the 
bottom  of  the  thread  is  as  large  as  the  rod  still  fail  by  breaking 
in  the  thread. 

In  order  to  secure  full  rod  strength  in  an  upset  bolt,  the  mill- 
wright must  see  that  the  bolts  are  upset  more  than  will  give 
full  bolt  size.  For  a  1-inch  bolt,  the  steel  should  be  upset  to  1%- 
inch  diameter,  giving  a  diameter  at  bottom  of  thread  of  1.16 
inches.  For  a  %-inch  bolt,  the  upset  and  thread-bottom  diameters 
should  be  1  inch  and  0.837  inch  respectively.  A  %-inch  bolt 
should  be  upset  to  %  inch  and  the  thread  should  cut  to  0.620  inch 
in  diameter. 

BOLT  FAILURE  BY  SHEARING. 

Bolts  do  not  always  fail  by  purely  tensile  stress.  Under  some 
conditions,  bolts  fail  by  shearing,  the  heads  being  torn  off  as 
shown  at  a,  Fig.  80.  At  first  sight  it  would  appear  as  if  this  were 
a  tensile  failure  due  to  the  weakening  of  the  steel  fibers  by  upset- 
ting the  metal  during  the  formation  of  the  head.  Doubtless  the 
metal  was  weakened  in  this  manner  to  a 
certain  extent,  but  the  failure  of  the  bolt 
as  shown  is  due  to  a  combination  of  both 
tension  and  shearing  strains. 

In  the  %-inch  bolt  described  above,  and 
which  was  under  5000  pounds  tension, 
there  was  a  tendency  of  the  bolt  to  pull 
through  the  head  along  the  dotted  lines 
b  c.  The  diameter  of  this  bolt  being 
y8-inch,  its  circumference  is  2%  inches, 
hence  each  inch  of  the  circumference  along 
the  lines  b  c  is  under  a  shearing  stress  of 
5000-^2.75^1820  pounds.  As  the  shearing 

strength  of  soft  steel  is  about  80%  of  its  tensile  strength, 
or  about  48,000  pounds  to  the  inch,  the  thickness  of  the  bolt  head 
in  order  to  barely  hold  itself  against  the  shear,  would  be  1820-=- 
48,000=0.038  inches. 

As  the  hexagonal  head  of  a  %-inch  bolt  is  actually  0.725 
inch,  the  shear  area  would  be  2.75X0.725=2  nearly,  hence 


FIG.  80.  SHEARING 
STRAINS  IN  A  BOLT 
HEAD. 


STRENGTH  OF  MATERIALS  187 

there  is  2  square  inches  of  metal  to  carry  5000  pounds  of  shear 
stress,  or  about  2500  pounds  to  the  square  inch.  As  each  inch 
is  good  for  48,000,  the  bolt  will  have  a  factor  of  safety  against 
shear  of  over  19,  consequently  there  is  little  likelihood  of  the  head 
stripping  off  the  rod  along  the  lines  b  c.  But  the  presence  of 
shear,  and  the  leverage  of  the  edges  of  the  head,  is  probably  what 
gives  the  conical  shape  to  the  break  at  a,  which  is  almost  always 
observed  when  a  bolt  head  is  pulled  off  by  direct  stress.  And  the 
thinner  the  head  the  more  cone-shaped  will  be  the  break  a. 

By  making  use  of  the  hints  given  above,  the  millwright  will 
be  able  to  work  out  the  several  stresses  present  in  machine  erec- 
tion, and  the  strains  must  be  opposed  by  adequate  arrangements 
to  carry  them.  It  is  the  lack  of  comprehension  of  the  strains  ever 
present,  and  the  lack  of  proper  timbering  to  absorb,  oppose  or 
carry  the  several  strains,  which  makes  the  shackly,  insecure  and 
flimsy  character  of  the  millwrighting  frequently  met  with  in 
some  mills. 


CHAPTER  XI. 

LAYING  OUT  SHAFTING. 

"How  big  a  shaft  is  needed  to  carry  100  horse-power  ?"  This 
question  is  asked  of  the  millwright  many  times  during  the  year, 
and  sometimes  the  millwright,  too,  has  hazy  ideas  regarding  that 
important  matter.  The  size  of  shaft  necessary  to  transmit  100 
horse-power  depends  of  course  upon  the  speed  at  which  it 
revolves.  If  the  speed  of  any  shaft  be  doubled,  it  will  carry  twice 
as  much  power.  This  rule  applies  to  belts  and  to  pulleys,  as  well 
as  to  shafts. 

The  speed  of  a  shaft  is,  then,  an  important  factor  in  laying 
out  a  power  transmission.  The  proper  speed  for  any  layout  is 
that  which  will  permit  the  required  speeds  to  be  obtained  without 
the  use  of  excessively  large  or  very  small  pulleys.  If  a  lot  of  fan 
blowers  or  fast  running  generators  (electric)  were  to  be  driven, 
the  shaft  should  be  given  a  higher  speed  than  if  paint  mixers  and 
foundry  tumbling  barrels  were  to  be  handled. 

HORSE-POWER    OF    SHAFTING. 

For  general  mill  work,  150  to  300  revolutions  a  minute  for 
shafting  covers  the  usual  practise  and  200  is  the  usual  speed  used 
by  the  writer  unless  conditions  call  for  some  other  speed.  The  use 
of  tables  for  determining  the  size  of  any  shaft  for  certain  work 
is  not  very  good  practise  although  it  does  well  enough  for  sec- 
ondary shafts,  counters  and  very  light  line  shafts.  For  such 
work,  a  fairly  good  rule  is  to  multiply  the  cube  of  the  diameter 
by  the  number  of  revolutions  a  minute  and  divide  the  product 
by  90.  The  quotient  will  be  the  number  of  horse  power  the  shaft 
should  transmit  -safely.  If  the  diameter  of  shaft  is  to  be  found, 
assume  a  speed  at  which  the  shaft  is  to  run.  Then  multiply  the 
horse-power  by  90,  divide  by  the  number  of  revolution::  and 
extract  the  cube  root  of  the  quotient. 

188 


LAYING  OUT  SHAFTING  189 

..,  90XHP  90XHP   UTD     d3xR 

By   algebra:    d3=     — — ,   R=  -^— ,  HP=  _-,  where 

HP=horse-power, 

d=diameter  of  shaft,  and 
Rz=  revolutions  to  the  minute. 

In  hanging  shafting,  the  bearings  should  be  so  arranged  that 
the  deflection  will  not  be  more  than  1/100  of  an  inch  to  each  foot 
of  length.  This  deflection  is  to  include  the  pull  of  belts,  the 
weight  of  pulleys  and  every  known  load  which  can  be  placed 
upon  shafting.  The  stiffness  of  a  shaft  is  not  the  strength  by  any 
means.  A  wire  cable  may  have  strength  enough  to  do  all  the  work 
of  a  shaft,  but  the  cable  does  not  have  the  stiffness  necessary  to 
carry  a  load  of  pulleys  and  pulls,  therefore  it  would  be  of  no  use 
as  a  shaft. 

TORSION  IN  A  SHAFT. 

We  meet  with  a  new  form  of  stress  when  shafting  is  to  be 
dealt  with,  and  in  addition  to  tension,  compression  and  trans- 
verse strains,  we  have  the  new  one  of  torsion,  or  twisting.  But 
this  is  an  old  acquaintance  under  a  new  name,  for  the  strains 
produced  in  any  material  by  torsion  are  those  due  to  shear,  and 
by  nothing  else.  When  a  severe  load  causes  a  shaft  to  break, 
the  strains  set  up  in  the  shaft  are  those  of  shear  entirely.  No 
other  strain  is  present  except  that  of  the  transverse  load  due  to 
the  weight  of  the  shaft  and  the  pulleys  located  upon  it. 

The  amount  of  torsion  in  any  shaft  should  not  be  enough  to 
permit  a  deflection  of  more  than  one  degree  in  30  diameters  of 
the  shaft.  That  is,  a  2-inch  shaft  5  feet  long  shall  not  twist  more 
than  one  degree  when  under  full  load,  with  the  power  applied  at 
one  end  and  taken  off  at  the  other  end  of  the  shaft.  It  means 
that  a  2-inch  shaft  would  have  to  be  1800  feet  long  before  the 
allowable  twist  would  allow  it  to  make  one  complete  revolution. 

The  bending  of  any  shaft  is  calculated  exactly  as  if  it  were  a 
beam  and  the  weight  of  the  shaft  constitutes  a  uniform  load  while 
the  pulleys  and  the  belt  pull  constitute  position  loads  and  they  are 
figured  accordingly  when  seeking  to  ascertain  the  diameter  of 
shaft  necessary  to  span  a  required  distance  within  the  allowable 
deflection. 


190  MILLWRIGHTING 

TWISTING  MOMENT  OF  SHAFTS. 

The  load  upon  any  shaft  is  called  the  "twisting  moment"  and  it 
is  found  by  adding  together  the  products  of  the  radii  of  all  the 
pulleys  after  each  has  been  multiplied  by  the  belt  pull  upon  each 
pulley.  All  the  pulleys  that  take  power  from  the  shaft  are  to  be 
thus  treated,  while  the  pulley  which  delivers  power  to  the  shaft 
is  to  be  treated  in  a  similar  manner,  but  by  itself,  and  the  product 
of  that  belt  pull  and  the  radius  of  its  pulley  will  be  found  to  equal 
the  sum  of  all  the  other  belt-radius  products.  Thus  the  greatest 
twisting  moment  will  be  found  between  the  driving  pulley  and  the 
power  pulley  next  adjoining  that  pulley,  but  the  bending  or  twist- 
ing power  may  be  divided  at  the  drive  pulley  by  a  portion  of  the 
stress  being  delivered  to  pulleys  on  either  side  of  the  driving 
pulley. 

TORSIONAL  STRESS. 

When  a  twisting  moment  exists  in  any  shaft  (by  twisting 
moment  is  meant  that  the  actual  twisting  force  at  the  rim  of  the 
pulley  is  equal  to  the  force  called  "twisting  moment"  which  acts 
one  inch  from  the  center  of  the  shaft,  or  acts  with  a  one  inch  lever- 
age) the  stress  thus  set  up  is  known  as  "tortional"  stress,  and,  as 
stated,  is  a  purely  shearing  stress,  as  illustrated  in  a  flange  coupling 
where  the  twisting  moment  tries  to  shear  off  the  coupling  bolts. 
The  same  action  is  trying  to  take  place  at  every  point  in  the  shaft 
along  its  entire  length.  This  torsional  or  shearing  stress  is 
resisted  by  what  is  known  as  the  "resisting  moment"  which  is 
equal  to  the  sum  of  all  the  moments  of  the  shearing  stresses  about 
the  axis  of  the  shaft. 

It  has  been  found  that  if  the  unit  stress  or  working  torsional 
strength  of  the  shaft  material  be  represented  by  S,  a  very  close 
approximation  of  the  horse-power  of  any  shaft  is  : 


Hp= 


321,000  ' 

where  J=the  diameter  of  the  shaft;  n,  the  number  of  revolu- 
tions a  minute,  and  S,  the  working  stress,  say  10,000  pounds  to 
the  square  inch.  The  above  formula  is  based  upon  the  supposi- 
tion that  where  7lf=the  twisting  moment,  0.1963  S  d3=M, 


LAYING  OUT  SHAFTING  191 

STIFFNESS  OF  SHAFTS. 

The  stiffness  of  a  shaft  depends  upon  the  coefficient  of  elastic- 
ity of  the  steel,  and  that  matter  like  others  of  its  kind  the 
millwright  must  study  in  books  devoted  to  that  subject,  as  it 
is  too  tedious  a  subject  to  permit  of  its  being  discussed  here  to 
any  length,  but  briefly  stated,  the  stretch  of  any  shaft  or  piece 
of  metal  depends  upon  its  coefficient  of  elasticity,  which  is  taken 
as  follows  by  some  authorities: 

COEFFICIENTS  OF  ELASTICITY. 

MATERIAL.  AVERAGE    COEFFICIENT. 

Steel 30,000,000  pounds  to  the  square  inch. 

Wrough  iron   ....27,500,000       "         "     " 

Cast  iron  15,000,000       "         "     " 

Timber    1,800,000 

That  is,  the  unit  stress  divided  by  the  unit  stretch  will  equal 
the  coefficient  of  elasticity.  Or  a  bar  of  steel  (a  rod)  %-mch 
in  diameter  and  20  feet  long  is  loaded  with  5000  pounds  pull: 
How  much  does  the  rod  stretch?  The  solution  of  this  problem 
will  be  to  multiply  the  pull  by  the  length  of  the  rod,  and  divide 
the  product  by  the  area  of  the  rod  times  the  coefficient  of  elas- 
ticity. If  the  sectional  area  of  the  rod  is  S=0.6  inch,  and  the 
length  L=20XX  12=240  inches,  and  the  coefficient  of  elasticity 
E=30,000,000  pounds  the  stretch  of  the  rod  is  found  as  fol- 

P  L          5000X240 
lows:  Deflect™  D=— =^^-^=0.0667  mches,  the 

stretch  of  the  rod  under  the  given  conditions. 

COEFFICIENTS  OF  ELASTICITY  FOR  SHEAR. 
The  same  rule  is  applied  to  the  torsion  of  shafts,  and  the 
coefficients  of  elasticity  for  shear  are  about  two-fifths  the  regu- 
lar coefficients  of  elasticity,  thus,  for  steel,  11,000,000  pounds, 
for  wrought  iron  10,000,000,  and  for  cast  iron  6,000,000  pounds, 
and  this  coefficient  may  be  represented  by  Ex,  and  worked  into 

the  formula:  HP=—   .    The  letters  have  the  same  mean- 

321,000 

ing  as  when  that  formula  was  used  for  ascertaining  the  horse- 
power, and  it  can  be  proven  that  when  a  2-inch  shaft  is  twisted 
under  the  load  of  50  horse-power  the  angle  a,  through  which 


192  MILLWRIGHTING 

584  TL     36,800,OOOHPL 

this  20-foot  shaft  will  be  twisted,  is :  a— = — - 

Ej  d3  EAd4n 

^36,800,000  X  50  x  240  _ 
11,000,000X16X200 

The  shaft  20  feet  long  would  be  240-^2=120  diameters  in  length, 
and  120-^30=4,  the  permissible  number  of  degrees  the  shaft  could 
twist  without  getting  outside  the  limit.  As  the  twist  is  more 
than  thrice  the  allowable  number  of  degrees,  it  is  evident  that  the 
shaft  is  overloaded  and  that  the  strain  should  be  reduced  or  the 
diameter  of  the  shaft  increased. 

In  this  manner,  as  barely  indicated  above,  the  millwright  may 
"keep  tabs"  on  the  strength  and  stiffness  of  any  shaft  he  is  called 
upon  to  erect  and  by  going  more  deeply  into  the  subject  he  may 
soon  fit  himself  to  design  shafts  perfectly  adapted  to  any 
demands  made  by  given  conditions.  The  few  items  of  scattered 
information  given  above  are  merely  to  excite  a  desire  for  more 
knowledge  of  this  important  subject,  and  to  induce  the  progressive 
millwright  to  study  deeper  into  the  matter. 

FITTING-UP  A  SHAFT. 

The  size  and  length  of  a  shaft  having  been  decided  upon,  the 
millwright  must  couple  up  the  several  lengths  and  place  the  shaft 
upon  the  several  timbers  or  piers  prepared  for  it,  as  described  in 
a  previous  chapter  on  page  132.  The  first  thing  is  the  coupling 
together  of  the  shaft  lengths.  When  drawings  are  made  by  a  good 
engineer,  he  will  so  design  the  shaft  that  every  piece  has  at  least 
two  bearings.  It  is  pretty  poor  designing  to  find  a  shaft  with  a 
short  coupled  length  passing  through  only  one  bearing. 

The  lengths  of  shafts  used  should  depend  upon  their  diameter, 
the  number  of  pulleys,  and  the  manner  in  which  the  shaft  sup- 
ports and  buildings  are  arranged.  It  does  not  pay  to  put  in  pieces 
of  4  15/16-inches  shafts  24  and  28  feet  long,  although  shafts  may 
be  obtained  of  almost  any  length  up  to  40  feet.  It  is  too  much 
work  to  handle  such  shafts  and  shorter  pieces  should  be  used. 
No  length  of  shaft  should  be  laid  down  upon  any  drawing,  except 
in  extreme  special  cases,  where  the  length  of  shaft  is  so  great 
that  it  cannot  be  lifted  by  tackle  attached  in  two  places.  Shafts 
which,  when  loaded  with  their  pulleys  and  gears,  will  bend  under 
their  own  weight  when  hung  up  from  two  points,  as  above  noted. 


LAYING  OUT  SHAFTING  193 

are  too  long  to  be  handled  with  safety,  and  the  designer  should 
look  to  this  point  and  put  in  couplings  enough  to  enable  the  shaft- 
ing to  be  handled  with  safety  a^fter  the  pulleys  have  been  put  in 
place. 

SHAFT  DRAWINGS. 

It  is  almost  an  absolute  necessity  nowadays  to  make  a  drawing 
of  a  shaft  or  a  line  of  shafting.  The  day  of  marking  off  the  length 
of  a  piece  of  shafting  on  a  pole,  and  then  sending  the  pole  to  the 
machine  shop,  has  gone  past.  The  shaft  manufacturer  wants  a 
drawing  of  the  shaft,  simple  though  it  may  be,  which  shows  every- 
thing which  is  to  go  on  the  shaft  and  which  shows  it  in  such  a 
manner  that  no  questions  need  be  asked  which  the  drawing  and 
the  accompanying  specifications  do  not  answer. 

Fig.  81  represents  the  type  of  shaft  drawings  used  by  the 
writer.  Drawings  should  be  made  about  24x36  inches,  and  several 
shafts  can  be  laid  down  on  the  same  sheet.  The  drawings  should 
be  made  1  inch  to  the  foot,  or,  if  there  is  very  little  on  a  shaft, 
it  may  be  made  l/2  inch  to  the  foot  with  larger  details  whenever 
necessary.  The  drawing  here  shown  is  for  the  main  line  of  a  fac- 
tory fitted  with  a  125-h.p.  Corliss  engine  which  belts  to  the  60x20- 
inches  pulley  shown  near  the  middle  of  the  shaft. 

It  is  the  invariable  custom  of  the  writer  when  laying  down  a 
factory  to  number  each  and  every  shaft  in  the  plant.  Commen- 
cing at  the  engine,  or  at  one  engine  if  there  be  several,  the  shaft  of 
that  machine  is  marked  with  a  figure  1  inside  a  small  circle, 
thus:(jY  The  shaft  to  which  the  engine  is  belted  is  marked  (g). 
Then  each  and  every  shaft  which  carries  a  pulley  is  given  a 
number  in  the  same  manner,  the  several  numbers  being  always 
in  sequence,  and  no  numbers  are  omitted.  The  shaft  of  each 
and  every  machine  which  receives  power  from  any  shaft  is  given 
a  number,  and  that  number  is  carried  on  the  drawings,  be  they 
simple  or  elaborate,  and  it  is  also  carried  through  the  specifica- 
tions, through  the  buyer's  list  and  the  erector's  list,  thereby  form- 
ing a  system  which  renders  it  impossible  for  any  man  to  assemble 
the  machinery  of  transmission  in  a  wrong  manner. 

Referring  to  Fig.  81,  it  will  be  noted  that  the  drawing  is 
marked:  "(g) Main  Shaft  a,  b,  c,  (200  r.p.m.)"  The  number  in  the 
circle  refers  to  the  corresponding  number  on  the  drawings  which 


194 


MILLWRIGHTING 


1  Pulley,  3/x  lo's.  3 
G.K.S.  &  K.  to  (£) 

I  Pillow  Block,  315Xa  x 
B.  &  S.  R.O 

1  Pulley,  2e"x  s"x  S15/ 
C.K.S.  &  K.  to     T\ 


1  Pulley,  36  x  12  x  315/J9 
F.K.S.  &  K.  to  (3^ 

1  Pillow  Block,  315/"  x  5 
B.  &  S.  E.G. 

1  Pulley,  26"x  6"x  S15/^' 
C.K.S.  &  K.  to  (££) 

1  Pulley,  18"x  sVa'^ia 
C.K.S.  &  K.  to  u 


1  CompressloQ  Coupling, 


Pulley,  36"x  I2"x  *7'^ 
F.K.S.  &  K.  is'long  to 
I  Pillow  Block.  47/1g  x  6 

B.  &  S.  E.O. 
1  SafetySet  Collar, 


1  Pulley,  60"x  20"x  47/w 
C.K.S.  &  K.  from  (£) 

Pillow  Block,  4^  x  6% 

1  Pair  Flange  Couplings, 

w*  x  3%"K.S. 
'Keys  &  Bolts. 


jjrz        TU-1  Pulley>  48  x 

^      '  ~\  C.K.S.  &  K. 


Pulley,  48"x  12"x  315/i» 


<_ 1  Pillow  Block,  3%x  5; 

B.  &  S.  K.O. 


FIG.    81.— LAYING    OUT    A    SHAFT. 


LAYING  OUT  SHAFTING  195 

chances  to  show  the  main  line.  The  number  "(2)"  is  also  found 
in  the  several  lists  as  will  be  shown  hereafter.  Next,  the  name 
''main  shaft"  speaks  for  itself,  and  is  beyond  contradiction  or 
wrong  interpretation.  Next,  in  parenthesis,  is  the  speed  of  the 
shaft  (200  r.p.m.)  settling  the  fact  that  the  shaft  is  to  run  at  that 
speed. 

Next  on  the  drawing  comes  a  dimension  line  showing  the  total 
length  of  the  shaft,  and  then  comes  another  line  of  dimensions 
which  shows  the  distances  apart  of  the  bearings.  Nothing  else  is 
put  in  this  line  of  dimensions,  and  when  the  millwright  comes  to 
erect  the  bridge-trees  he  need  only  look  at  this  line  of  dimensions. 
He  has  no  need  of  searching  for  the  timber  dimensions  or  dis- 
tances among  a  dozen  other  figured  distances.  A  single  glance 
locates  all  the  bearings  from  either  end  of  the  shaft,  and  ties  them 
all  to  each  other. 

Then  comes  a  line  of  dimensions — local  dimensions  they  may 
well  be  called,  for  they  extend  from  every  pulley  center  to  ends  of 
shaft,  to  centers  of  bearings,  and  to  the  center  line  of  building 
walls  if  there  chance  to  be  any.  But  the  manner  in  which  these 
dimensions  are  derived  gives  them  great  accuracy,  and  they  form 
a  never-failing  check  by  which  each  of  the  other  lines  of  dimen- 
sions may  be  verified.  The  figures  in  this  line  were  obtained  by 
scaling  the  drawing,  of  course,  but  not  by  scaling  from  one  dimen- 
sion line  to  the  next.  That  method  never  fails  to  involve  the  mill- 
wright in  error  and  vexatious  delay.  Instead  of  being  laid  down 
by  scaling  the  drawing  step  by  step,  the  dimensions  in  this  line 
are  really  derived  dimensions  and  they  were  all  taken  from  the 
next  line  nearer  to  the  shaft. 

It  is  the  invariable  custom  of  the  writer,  either  when  taking 
dimensions  for  the  purpose  of  making  a  drawing  or  when  working 
from  a  drawing,  to  use  fundamental  dimensions,  and  to  work  at 
all  times  from  the  same  point  rather  than  working  from  one  point 
to  another.  It  is  like  the  man  cutting  off  bits  of  board  to  a  pat- 
tern. As  long  as  he  marks  them  all  from  the  same  pattern,  he 
will  get  the  lengths  somewhere  uniform,  but  should  the  man 
saw  off  one  piece  and  take  that  one  to  mark  the  next  with  the 
little  piece  of  board  last  cut  would  probably  need  an  introduction 
to  the  pattern  should  it  ever  happen  to  get  next  again. 

The  line  of  dimensions  called  the  "local"  dimensions,  and,  in 


196  MILLWRIGHTING 

fact  all  the  other  lines  of  figures,  were  derived  from  the  second 
row  of  figures  from  the  shaft.  A  beginning  is  always  made  from 
the  end  of  the  shaft  the  most  convenient  for  this  purpose,  and  the 
bearing  nearest  to  the  end  chosen  is  marked  I.  The  next  bearing 
is  marked  II,  the  others  III,  IV,  etc.,  to  the  other  end  of  the  shaft. 
In  further  drawing  or  designing  operations,  the  end  of  the  shaft 
nearest  bearing  I  is  always  taken  as  a  starting  point. 

All  the  shaft  measurements  in  this  case  are  taken  from  the 
end  of  the  shaft,  though  in  some  cases  they  may  be  taken  from  a 
point  at  a  distance  from  the  shaft,  or  from  some  other  shaft.  Com- 
mencing at  the  end  of  the  shaft,  the  millwright  finds  it  to  be  13 
inches  to  the  center  of  the  first  thing  on  the  shaft,  which  happens, 
in  this  case,  to  be  a  pulley.  The  distance  is  marked  in  its  place, 
and  witness  marks  indicate  the  points  or  lines  between  which  the 
measurement  was  made.  To  obtain  the  next  dimension,  which 
chances  to  be  the  center  of  a  bearing,  the  distance  is  scaled,  not 
from  the  center  of  the  pulley,  but  from  the  end  of  the  shaft  from 
which  the  first  measurement  was  taken.  This  distance  is  found 
to  be  2  feet  six  inches,  and  it  is  so  entered  as  close  as  convenient 
to  the  center  line  of  the  bearing  and  it  will  be  noted  that  there 
is  but  one  witness  mark  made  for  this  dimension,  and  that  one 
on  the  bearing  center  line.  For  the  other  end  of  this  measurement, 
the  witness  mark  made  at  the  "beginning  end"  of  the  shaft  still 
prevails. 

The  scaling  and  measuring  is  continued  in  this  manner  until 
the  other  end  of  the  shaft  has  been  reached,  and  the  measurement 
to  that  point  is  found  to  be  42  feet.  This  gives  the  over-all  dimen- 
sion of  the  shaft  without  any  figuring  or  adding  of  other  dimen- 
sions. To  obtain  the  "local"  dimensions,  it  is  only  necessary  to 
subtract  the  scaled  dimensions  one  from  another,  and  the  several 
quotients  are  the  "local"  distances  between  each  of  the  pulleys,  the 
bearings,  or  between  bearings  and  pulleys,  as  the  case  may- be. 

To  obtain  the  dimensions  in  the  second,  or  "bearing"  row,  it  is 
only  necessary  to  subtract  from  one  another  the  dimensions  found 
next  to  the  witness  marks  at  the  ends  of  the  shaft  and  at  the 
several  bearing  center  lines.  For  instance :  the  distance  is  required 
between  bearing  IV  and  V.  Upon  the  line  of  scaled  dimension  is 
found  the  figures  24  feet  7  inches,  and  31.  feet  9  inches.  Sub- 
tracting the  former  from  the  latter  leaves  7  feet  2  inches,  which  is 


LAYING  OUT  SHAFTING  197 

found  to  be  the  distance  laid  down  between  bearings  IV  and  V. 
In  this  manner,  by  making  a  single  subtraction  the  direct  distance 
between  any  two  of  the  "points"  on  the  main  shaft,  Fig.  81,  may 
be  found  without  further  scaling  or  calculation.  It  is  a  great 
"error-saving"  method. 

In  the  line  of  dimensions  next  to  the  shaft,  and  almost  smoth- 
ered among  the  pulleys,  may  be  found  another  little  row  of  figures. 
These  are  from  which  to  obtain  the  length  of  each  key-way.  The 
machinist  who  makes  the  shaft  must  have  this  line  of  dimensions, 
or  he  invariably  gets  the  key-seats  just  where  you  want  to  place  a 
bearing.  Then  there  is  an  opportunity,  which  you  always  take,  of 
trying  to  fill  key-seats  with  cuss-words. 

Note  that  the  key-seat  dimensions  are  either  "tied"  to  the  ends 
of  the  shaft  or  to  each  other,  so  that  in  laying  out  the  splining  a 
man  can  begin  at  one  end  of  a  shaft  and  work  along  as  far  as  the 
dimensions  are  found ;  then  he  commences  at  the  other  end  of  the 
piece  of  shafting  and  repeats  the  operation  until  he  finds  no  more 
dimensions,  whereupon  he  may  quit  that  shaft  in  confidence  that 
he  has  not  overlooked  any  key-seats. 

Upon  the  opposite  side  of  the  shaft,  in  Fig.  81,  is  found  what 
may  well  be  known  as  the  "fool-killer's  list."  That  list  contains, 
in  plain  English,  the  name,  dimensions,  description,  and  its  con- 
nection with  other  shafting  if  any,  of  each  and  every  piece  of 
machinery  placed  upon  the  shaft.  In  making  the  assembly  of  a 
shaft  from  a  drawing  as  above,  the  millwright  can  safely  leave  the 
work  to  any  man  who  can  read.  He  cannot  make  a  mistake  unless 
he  does  it  on  purpose. 

It  has  long  been  the  method  of  the  writer  to  make  two  lists  of 
the  material  to  be  found  upon  the  shaft,  and  upon  other  shafts  in 
the  same  job.  The  first  list,  which  may  be  known  as  "the  erector's 
list/'  is  as  follows : 

ERECTOR'S  LIST. 

(1)     Engine,  (85  R.P.M.) 

1  Corliss  steam  engine,  simple,  non-condensing,  prefer- 
ably 14x30  inches,  but  ample  to  give  100  indicated 
horse-power  with  100  pounds  boiler  pressure,  cut- 
ting off  at  y4  stroke. 

1  Pulley,  120x20  inches,  furnished  with  machine  (to 
No.  2-b). 


198  MILLWRIGHTING 

(2)     Main  line  shaft,  3  15/16  and  4  7/16  inches  x  42  feet 

(200  r.p.m.).     In  three  pieces,  a,  b,  c. 
(2a)  1  Shaft,  3  15/16  inches  x!6  feet,  4  key-seats. 

1  Pulley,  34x10x3  15/16  inches,  C.  K.S.  &  K.  to  (4). 
43  feet  of  10-inch,  8-ply  I.S.C.  belt  (2a  to  4). 

1  Pillow-block,  3  15/16x5%-inches  drop,  B.  &  S.  R.  O. 

2  Bolts,  1x14  inches,  with  nut  and  check  nut,  1  cut  and 
1  cast  washer  1%  inches  in  diameter  hole. 

1  Oil-cap  and  nipple,  %-inch  pipe,  12  to  36  inches  long, 
tapped  into  cap  of  journal  bearing.  No  thread  on 
upper  end  of  pipe,  the  end  being  loosely  closed  by  a 
%-inch  nipple  screwed  into  a  %-inch  cap  and  placed 
over  the  %-inch  pipe. 

1  Pulley,  26x8x3  15/16  inches,  C.  K.S.  &  K.  to  (5). 
48  feet  of  belt,  8-inch,  6-ply,  I.S.C.  (2a  to  5). 

1  Pulley,  36x12x3  15/16  inches,  F.  K.S.  &  K.  to  (3). 
52  feet  of  belt,  6-inch,  I.S.C.  (2a  to  3). 

1  Pillow-block,  3  15/16x5%-inch  drop,  B.  &  S.  R.O. 

2  Bolts,  1x12  inches,  with  nut  and  check  nut,  1  inch 
cast  and  1  cut  washer,  1%-inch  hole. 

1  Oil-cap  and  nipple. 

1  Pulley,  26x6x3  15/16  inches.    C.  K.S.  &  K.  to  (12). 

and  so  on  through  the  list. 

At  the  end  of  the  shaft  a,  the  coupling  is  specified  as : 
1  Compression  coupling,  3  15/16x4  7/16  inches,  Shaw, 

or  its  equivalent  (2a  to  2b). 

And  in  connection  with  compression  couplings  hangs  quite  a 
tale  which  will  be  told  later.  Another  item  is : 

1  Pulley,  36x12x4  7/16  inches.  F.  K.S.  &  S.S.  &  K. 
18  inches  long  to  (8). 

By  this  the  millwright  knows  that  the  36-inch  pulley  has  a 
12-inch  face  and  is  bored  47/16  inches.  The  letter  "F"  means 
that  the  face  is  flat  or  straight  and  "K.S."  indicates  that  the  pulley 
is  to  be  key-seated.  "S.S."  shows  that  it  is  to  be  set-screwed  as 
well,  and  "K.  18  inches  long"  indicates  that  a  straight  key  is 
desired,  18  inches  long,  upon  which  the  pulley  can  be  moved  at 
will  by  simply  loosening  the  set-screws.  Other  pulleys  are  marked 
simply  "K.S.  &  K.,"  or  "C.  S.S."  or  "F.  K.S.,"  or  "F.  S.S,,"  etc,, 
meaning  that  the  pulleys  thus  marked  are  to  be  fitted  with  "key- 
seat  and  key,"  crowned  face,  set-screwed;"  "flat  face  (straight) 
key-seated,"  or  "flat  face,  set-screwed,"  as  the  letters  indicate. 
The  pillow-blocks  are  marked  "B.  &  S.  R.O."  to  indicate  that  they 
are  "ball  and  socket,  ring  (or  chain)  oiling,"  etc.,  and  to  dis- 


LAYING  OUT  SHAFTING 


199 


tinguish  them  from  solid  bearings  the  latter  should  be  plainly  spe- 
cified as  "1  rigid  flat  box"  or  "pillow-block,"  if  you  prefer.  The 
belt  is  marked  "I.S.C.,"  indicating  the  fact  that  it  is  to  be  "impreg- 
nated stitched  cotton,"  or  in  other  words,  plain  Gandy.  But  so 
many  people  have  gone  into  manufacturing  that  kind  of  belting 
that  the  terms  "Gandy,  Original  Gandy,  Rub-Oil,  Leviathan, 
Mount  Vernon,"  etc.,  have  become  so  numerous,  and  so  mixed  up 
are  the  originals,  the  substitutes,  the  paraffin-filled  and  the  linseed- 
filled  varieties,  that  no  man  can  afford  to  call  any  particular  name 
in  the  specifications.  Let  the  millwright  specify  the  "I.S.C."  and 
select  from  them  in  accordance  with  the  specifications  for  the 
different  varieties  of  belting  to  be  found  on  page  247. 

The  compression  coupling  is  specified  as  "Shaw  or  its  equiva- 
lent."   Here  is  where  another  imitation  has  butted  in.    There  are 


FIG.   82.— A  COMPRESSION   COUPLING  WHICH  HOLDS. 

several  double  compression  couplings  on  the  market  which  to  the 
casual  glance  appear  to  be  exactly  alike,  but  one  particular  method 
of  bolt  arrangement  provides  a  coupling  which  will  hold  without 
ever  giving  trouble,  while  some  of  the  other  bolt  arrangements 
fail  to  hold  the  cones  to  the  shaft  with  sufficient  force  to  prevent 
slipping.  Hence  the  specifying  of  the  coupling  which  will  hold, 
or  its  equivalent,  which  enables  the  millwright  to  obtain  bids  from 
other  makers  of  couplings. 

A  view  of  this  coupling  is  shown  by  Fig.  82,  and  another 
coupling,  almost  similar  in  appearance,  is  shown  by  Fig.  83.  The 
alternate  bolt  arrangement  shown  by  Fig.  82  always  holds  the 
coupling  securely,  no  matter  what  strain  may  be  placed  upon  the 
shaft.  In  fact,  the  shaft  could  probably  be  twisted  completely  in 
two  before  this  coupling  would  slip.  But  with  the  arrangement 
of  bolts  shown  by  Fig.  83  the  coupling  frequently  fails  under  loads 


200 


MILLWRIGHTING 


which  would  be  carried  easily  by  the  other  arrangement  of  com- 
pression bolts.  The  only  difference  is  that  in  Fig.  82  the  rings 
or  collars  which  clamp  the  heel  and  the  toe  of  the  split  compression 
cone  are  connected  together.  In  Fig.  83  the  two  rings  on  the 


{ 


-i 


FIG.    83.— DEFECTIVE   BOLT  ARRANGEMENT   IN  A   COMPRESSION 
COUPLING. 

heel  are  connected  by  the  bolts,  likewise  the  two  collars  on  the  toe 
are  connected  by  the  other  or  longer  set  of  bolts.  Thus  there  is 
no  equalizing  between  the  heel  and  toe  pressures  as  there  is  when 
they  are  cross-connected  as  in  Fig.  82. 

FLANGE  OR  PLATE  COUPLINGS. 

A  little  further  in  the  erector's  list  will  be  found  items  as  .fol- 
lows : 
(2b)    (Continued.) 

1  Flange  coupling,  15%x4  7/16  inches,  K.S.  &  K.,  fit- 
ted to  shaft,  but  loose,  to  (2c) 

(2c)   1  Shaft,  3  15/16  inches  x  16  feet,  3  K.S.  (200  r.p.m.) 
1  Flange  coupling,  15x3  15/16  inches,  K.S.  &  K.,  and 
bolts,  and  driven  on  shaft.   From  (2b). 

Here  a  flange  coupling  is  specified  which  connects  two  shafts 
of  different  diameters.  It  is  also  specified  that  one  of  the  coup- 
lings shall  be  fitted,  but  not  driven  fast  upon  the  shaft.  This 
matter  is  very  important  to  the  millwright,  for  unless  the  pulleys 
are  all  of  the  split  variety  they  cannot  be  put  upon  the  shafts 
where  both  couplings  have  been  driven.  In  this  illustration,  one 
compression  and  one  flange  coupling  is  shown  for  the  purpose 
of  describing  the  two  forms  of  shaft  connection.  In  practice, 
the  couplings  would  be  all  of  one  kind,  either  compression  or 
flange,  or  some  other  kind. 

Were  the  couplings  of  the  compression  type  they  would  all  be 
left  loose,  and  nothing  needs  be  done  except  to  bore  the  inter- 


LAYING  OUT  SHAFTING 


201 


nal  cone  to  fit  the  sizes  of  shaft  they  are  to  be  used  upon.  But 
with  the  flange  coupling,  it  is  necessary  that  after  a  coupling 
has  been  fitted  the  shaft  should  be  put  in  the  lathe  and  the 
coupling  faced  up,  for  that  type  of  coupling  will  never  run  true 
until  it  has  been  faced  up,  as  described. 

A  new  flange  coupling  has  recently  been  placed  on  the  market 
from  which  great  things  seem  possible.  It  is  a  combination 
of  the  compression  coupling  illustrated  by  Fig.  82,  and  the  time- 
honored  flange  coupling,  which  is  the  best  ever  for  holding  shafts 
together,  but  which  is  despair  itself  when  pulleys  must  be 
changed — and  a  coupling  must  come  off ! 

IMPROVED  FLANGE  COUPLING. 

This  coupling  as  represented  by  Fig.  84,  is  a  combination 
of  the  flange,  compression  and  "horn"  couplings — the  latter  being 
a  three-piece  cut-off  coupling.  The  compression  cone  used  in 
this  coupling  is,  as  shown  in  the  engraving,  cut  in  two  in  the 


FIG.    84.— THE   HENDERSHOT    IMPROVED    FLANGE    COUPLING. 

middle  of  its  length,  instead  of  being  made  in  one  piece  like  the 
double  cone  used  in  Fig.  82.  The  flanges  shown  by  Fig.  84  are 
made  to  interlock,  thus  taking  the  strain  of  the  transmission,  and 
leaving  the  bolts  nothing  to  do  except  to  carry  their  tensile  load 
of  holding  the  cones  to  their  work.  The  cones  butt  against 
each  other,  and  the  shafts  may  be  accurately  alined  in  the  coup- 


202  MILLWRIGHTING 

ling  by  letting  one  shaft  project  y2  inch  into  the  other  cone  in 
much  the  same  manner  that  the  shafts  are  thus  centered  in 
ordinary  flange  couplings. 

With  these  couplings  nothing  is  necessary  except  to  fit  them 
to  the  diameter  of  the  shafts  and  screw  up  the  bolts.  In  taking 
down  the  couplings,  the  cones  are  loosened  by  inserting  bolts 
in  threaded  holes  made  for  that  purpose,  and  then  backing  the 
cones  right  out  of  their  hubs. 

THE  BUYER'S  LIST. 

After  the  erector's  list  has  been  made  up  as  described, 
another  list  is  made  of  the  items  in  the  list  in  question,  bringing 
all  the  pulleys  together,  all  the  pillow-blocks  into  line,  and  all 
the  belting,  collars,  bolts,  washers,  oilers,  and  everything  else 
to  be  found  in  the  list.  A  section  of  the  list  will  be  as  follows : 

1  Pulley,  34x10x3  15/16  inches,  C.  K.S.  &  K.  (2a  to  4). 
1  Pulley,  26x8x3  15/16  inches,  C.  K.S.  &.  K.  (2a  to  5). 
1  Pulley,  36x12x4  7/16  inches,  F.  K.S.  &  S.S.  &  18- 
inch  K.  (2b  to  2). 

In  like  manner,  everything  in  the  erector's  list  is  compiled. 
The  writer  has  frequently  had  the  erector's  list  typewritten 
double  space,  then  with  a  sharp  knife  a  cut  was  made  between 
each  pair  of  items  and  the  resulting  slips  were  compiled  and 
pasted  on  another  sheet  of  paper,  from  which  made-up  copy 
the  necessary  number  of  buyer's  lists  were  typewritten.  From 
a  list  thus  made  it  is  possible  for  the  pulley  man  to  get  out 
the  bill  of  pulleys  complete  with  no  other  data — not  even  the 
shaft  drawing  being  necessary. 

The  buyer's  list  should  be  used  by  the  millwright  when  the 
shipment  of  machinery  is  checked  against  the  bill  of  lading. 
And  as  each  pulley  or  shaft  or  gear  is  checked,  let  a  number  be 
painted  in  white  paint  on  that  piece  of  machinery,  and  the  erec- 
tor knows  where  it  goes  and  what  shaft  it  goes  on  the  moment 
he  lays  his  eyes  upon  it.  Once  tried,  this  method  will  never  be 
abandoned  until  a  better  one  has  been  devised.  It  fills  the  bill 
pretty  well  thus  far. 

A  word  of  caution  as  to  belts.  When  specifying  them,  do 
not  give  the  length  of  each  belt  separately.  If  there  are  four 
8-inch  belts  of  48,  34,  54  and  27  feet,  just  lump  them  all  into 


LAYING  OUT  SHAFTING  203 

one  item  in  the  buyer's  list  and  specify:  163  feet  of  belt,  8-inch, 
6-ply  J.  S.  Cotton,  and  add  the  requirements  as  to  "pick"  weight 
of  yarn,  tightness  of  weave,  rilling,  etc. 

RECEIVING  MACHINERY  AT  THE  MILL. 

Upon  receipt  of  a  carload  of  machinery  at  the  mill,  the  mill- 
wright should  detail  a  trusty  assistant  to  check  the  shipment, 
using  the  bill  of  lading  and  the  buyer's  list,  and  carefully  com- 
paring each  piece  of  machinery  with  the  specifications  as 
regards  quality  and  agreement  with  the  list.  Have  all  shortages 
and  breakages  reported  at  once  to  the  railway  company,  accom- 
panied by  the  bills  of  lading  and  the  freight  bills.  Never  dis- 
pute with  the  local  agent.  Pay  the  freight,  receipting  for  the 
same  as  "in  bad  order,"  or  "short  so-and-so,"  as  the  case  may 
be  and  take  up  the  matter  with  the  claim  department  of  the 
road.  Nothing  is  gained  by  trying  to  do  this  kind  of  business 
through  the  local  agent.  Go  to  headquarters  at  once. 

As  each  piece  is  received  and  checked  have  it  marked  as 
described  with  the  shaft  number,  and  then  set  some  laborers  at 
work  cleaning  the  shipping  slush  off  the  shafting  and  other  bright 
work.  Never  try  to  erect  a  line  of  shafting  until  the  white  lead 
or  other  "dope,"  has  been  carefully  cleaned  off  and  replaced  with 
a  little  clean  oil;  the  key-seats  all  examined  and  touched  up 
with  a  file  wherever  a  corner  has  been  jammed.  Look  care- 
fully over  all  the  pulleys.  The  keys  should  either  be  shipped  in 
place  in  the  hubs  and  wedged  there  with  bits  of  wood,  or  they 
should  be  shipped  in  a  box,  packed  in  grease.  The  latter  way 
is  to  be  preferred,  for  many  a  key  has  been  lost  by  being  shipped 
tightly  wedged  into  place  by  a  bit  of  board  driven  in  sidewise 
between  the  key  and  the  opposite  side  of  the  hub.  The  wood 
shrinks  en  route,  the  key  becomes  loose  and  works  out — and  a 
kick  is  registered  of  key  shortage,  all  on  account  of  poor  packing. 

Have  a  man  try  every  key  into  its  pulley  and  into  the  proper 
key-seat  in  the  shafting.  Sometimes  trouble  is  found  in  this 
way,  and  such  trouble  can  be  remedied  much  easier  than  after  the 
shaft  is  hanging  in  mid  air,  and  all  hands  are  waiting  for  the 
trouble  man  to  get  out  of  the  way.  Let  all  the  bolts  be  looked 
over  and  the  threads  touched  up  where  they  happen  to  be  jammed. 
Nothing  is  more  aggravating  than  a  bolt  which  will  not  catch  the 


204  MILLWRIGHTING 

thread  in  the  nut,  especially  when  a  man  is  hanging  head  down 
trying  to  start  the  nut  into  place. 

LINING  OUT  FOR  A  SHAFT. 

The  bridge-trees  having  been  put  in  place  according  to  the 
drawing,  a  line  must  be  stretched  either  above  or  below  the  tim- 
bers, or  above  the  piers,  parallel  with  the  line  to  which  the  work 
is  to  be  done.  If  the  mill  has  been  equipped  with  permanent 
stations,  as  described  in  chapter  III,  it  is  only  necessary  to 
"pick-up"  these  stations  with  the  transit  and  then  transfer  a 
line  from  them  to  the  bridge-trees. 

The  station-rod,  as  described  in  chapter  III,  is  the  tool  for 
use  with  the  transit  when  lining  the  bridge-trees.  If  a  couple  of 
station  stones  have  been  placed  directly  under  the  center  of  the 
proposed  shaft,  then  set  up  the  transit  over  one  stone,  pick  up 
with  the  cross-hairs  the  center  mark  on  the  other  station  stone, 
and  the  instrument  is  ready  for  business. 

Let  a  man  place  his  pencil  on  the  edge  of  one  of  the  bridge- 
trees,  and  sight  to  the  bridge-tree  with  the  telescope,  directing 
the  pencil  to  be  moved  one  way  or  another  until  it  is  cut  by  the 
cross-hairs  of  the  transit.  Direct  the  workman  to  mark  the  place 
thus  located  which  is  a  point  in  the  shaft  line.  Proceed  in  like 
manner  to  mark  each  bridge-tree  and  then  the  pillow-blocks 
may  be  located  and  cut-in  directly  to  the  center  marks  thus 
made.  In  case  the  carpenters  (that's  what  they  call  millwrights 
on  the  job)  prefer  to  stretch  a  line  instead  of  working  directly 
to  transit-given  marks  on  each  bridge-tree,  then  mark  the  first 
and  last  timber  or  pier,  and  let  a  line  be  stretched  fair  with  the 
two  marks  thus  made. 

When  station  stones  have  not  been  provided  for  each  shaft, 
and  it  is  necessary  to  work  from  a  line  some  distance  at  one  side, 
then  set  up  the  transit  on  the  line  in  question,  locate  one  end  of 
the  shaft  line  about  where  it  should  come,  then  set  the  station- 
rod,  Fig.  4  (page  21),  with  the  scratch  point  #  upon  the  shaft 
center  mark  on  the  first  bridge-tree.  Bring  the  sliding  head  of 
the  rod  to  bear  on  the  cross-hairs,  then  clamp  the  rod  and  carry 
it  to  the  other  end  of  the  shaft  line.  Here  place  the  rod  hori- 
zontally as  before  and  at  right  angles  to  the  line  of  sight  (this 
must  also  be  done  at  the  first  station),  and  move  the  rod  until 


LAYING  OUT  SHAFTING  205 

the  head  intercepts  the  line  of  sight.  While  the  rod  is  in  this 
position,  make  a  mark  on  the  bridge-tree  with  the  scratch  point 
in  the  rod,  and  this  mark  will  be  in  the  desired  shaft  line. 

The  points  thus  found  may  be  carried  up  or  down  by  means 
of  a  plumb-line  or  a  spirit-level.  About  as  good  a  way  to  get 
the  marks  to  the  desired  vertical  hight  is  to  nail  a  bit  of  board 
in  a  vertical  position  upon  the  marks  on  the  bridge-trees.  Then 
a  line  may  be  stretched  at  the  desired  hight.  The  line  thus 
stretched  may  be  used  as  a  center  from  which  to  lay  out  on  either 
side  the  distance  the  bridge-tree  is  to  be  boxed  down  to  receive 
the  pillow-blocks. 

LEVELING  FOR  THE  SHAFT. 

The  next  step  is  to  level  from  one  bridge-tree  to  another 
until  each  one  is  marked  for  the  depth  of  cut  required.  This  may 
be  done  with  the  straight-edge  and  carpenters'  level,  or  with  the 
telescope  level.  A  sight  may  be  taken  across,  either  over  or 
under,  the  bridge-trees  and  measurements  taken  from  the  line  of 
sight  to  the  cutting  level  on  each  bridge-tree.  This  method  is 
preferable  when  a  telescope  instrument  is  available.  In  that 
case,  set  up  the  instrument  anywhere  so  that  a  view  is  obtained 
of  a  point  vertical  to  each  bridge-tree. 

If  the  instrument  be  located  a  few  feet  either  above  or  below 
the  shaft  level,  then  remove  the  sliding  heads  from  the  station- 
rod  and  the  leveling-rods,  insert  a  short  piece  of  wood  in  place 
of  the  regular  rod,  and  place  both  heads  upon  this  short  piece  of 
wood.  Set  the  scratch  point  on  one  of  the  bridge-trees,  just  hook- 
ing the  point  over  the  timber,  and  take  a  sight  at  the  sliding  head 
which  is  moved  to  the  line  of  sight.  Next,  carry  the  rod,  clamped 
as  above,  to  each  bridge-tree  in  turn  until  the  lowest  one  has 
been  found. 

Set  the  scratch  point  on  the  lowest  bridge-tree  at  the  level  of 
the  cut  which  should  be  made  for  the  pillow-block  on  that  timber. 
This  point  may  be  permanently  marked  for  the  bottom  of  the 
cut.  Then  carry  the  rod  to  each  other  bridge-tree  in  turn  and 
make  a  mark  on  each  for  the  bottom  of  the  cut,  as  described. 
It  should  be  kept  in  mind  during  all  operations  of  this  char- 
acter that  the  leveling-instrument,  the  transit,  builder's  level,  or 
whatever  instrument  may  be  used,  should  be  kept  in  an  absolutely 


206 


MILLWRIGHTING 


level  position  as  far  as  possible.     If  the  instrument  is  not  level, 
then  the  shaft  will  be  as  far  out  of  level  as  was  the  instrument. 

"CUTTING-IN"  PILLOW-BLOCKS. 

Fig.  85  shows  a  very  good  method  of  cutting-in  a  pillow-block. 
The  line  a  and  hight-mark  b  having  been  given  as  described,  pro- 
ceed to  find  the  line  g  for  the  bottom  of  the  pillow-block  cut. 
The  mark  g  may  be  made  by  gaging  from  the  upper  edge  of  the 
stick,  but  it  is  better  to  use  a  spirit-level  for  this  purpose,  as 
shown  at  d.  The  end-marks  e  and  /  are  made  by  measuring  out 
either  way  from  line  a.  Do  not  try  to  get  these  lines  by  using 
a  square  on  the  timber,  for  nothing  about  the  bridge-tree  can  be 
accepted  to  work  from  except  the  line  a  and  the  hight-mark  b. 


FIG.   85.— "CUTTING-IN"  A  PILLOW-BLOCK. 

As  far  as  other  tilings  go,  treat  the  timber  as  though  it  was  not 
standing  square  with  the  building,  the  line  a,  or  anything  else. 
In  fact,  work  only  from  the  two  points  mentioned  and  the  work 
will  come  out  right.  Work  from  timber  edges  and  there  will 
surely  be  trouble. 

Having  obtained  lines  e,  f,  and  g,  proceed  to  saw  the  ends  of 
the  cut,  then  saw  or  chop  down  to  the  line  every  three  or  four 
inches  along  the  length  of  the  proposed  cut,  as  at  h,  i,  j.  The  ax 
or  adze  may  be  used  instead  of  the  saw  if  preferred.  Then  cut 
through  one  of  the  sections,  taking  care  not  to  cut  too  deep  on  the 
back  side  of  the  timber.  In  fact  it  is  best  to  cut  very  light  on 
the  back  side  and  lay  in  the  spirit-level  as  shown  at  k,  and  grad- 
ually work  down  from  line  g  until  the  instrument  shows  a  flat 
level  cut  entirely  across  the  timber. 


LAYING  OUT  SHAFTING  207 

Next,  knock  out  another  section  at  /  and  proceed  to  cut 
through  as  before,  cutting  down  to  the  level  on  the  back  and  to 
mark  g  at  the  front.  Thus  having  obtained  a  level  surface  on 
three  sides  of  the  proposed  flat  surface,  the  center  may  be  quickly 
worked  down,  using  the  eye  to  keep  the  cut  from  going  too  deep. 
A  rabbet-plane  is  the  thing  to  run  through  the  end-cuts  with  while 
cutting  down  level.  Then  the  cuts  will  be  right  close  to  the  end- 
marks,  and  to  finish  up,  or  down,  the  center,  cut  away  the  bulk 
of  the  wood  with  ax,  adze  or  chisel,  then  finish  with  a  short 
jointer  or  a  good  fore-plane.  Use  the  corner  of  the  plane  as  a 
straight-edge  to  determine  when  the  cutting  is  deep  enough  at 
any  place.  By  turning  the  plane  diagonally  across  the  cut  and 
then  tipping  it  sidewise  a  little,  a  mighty  good  straight-edge  effect 
is  obtained,  and  the  millwright  sees  at  once  where  cutting  is  or 
is  not  needed. 

Never  leave  a  hollow  place  under  any  pillow-block.  If  by  any 
means  a  man  cuts  too  deep  in  any  portion  of  the  timber,  then  just 
mark  down  at  g  for  another  cut,  making  the  new  mark  at  a  depth 
which  will  just  work  out  the  defective  cutting  and  still  leave  the 
new  cut  the  thickness  of  a  standard  board,  either  y2,  %  or  % 
inches,  in  order  that  a  piece  of  wood  of  the  required  thickness 
may  be  quickly  found  without  its  having  to  be  dressed  to  the 
right  thickness.  Nail  the  board  in  place  in  the  bottom  of  the  cut 
and  take  care  that  the  nails  do  not  come  where  the  bolt-holes  are 
to  be  bored. 

It  is  well,  if  possible,  to  distribute  the  pillow-blocks  before  the 
cutting  is  done  as  above  described,  and  then  make  the  lines  e  and 
/  to  correspond  with  the  lengths  of  the  pillow-blocks.  Some- 
times the  castings  do  not  run  evenly,  and  sometimes  when  of  the 
same  length  there  will  be  more  of  this  length  on  one  side  than 
on  the  other.  Hence,  in  marking  at  e  and  /,  work  from  center 
line  a,  but  work  to  the  lengths  of  pillow-block  castings  as  well. 
Sometimes  there  is  a  slight  difference  in  the  reach  of  pillow-blocks. 
By  "reach"  is  meant  the  distance  from  the  center  line  of  the 
bearing  to  the  bottom  surface  of  the  pillow-block  casting.  Most 
of  the  high-grade  pillow-blocks  are  made  adjustable  in  hight 
through  a  limited  movement.  When  this  adjustment  is  present, 
the  cuts  may  all  be  made  level  to  mark  b,  but  where  there  is  no 
vertical  adjustment  to  the  pillow-block  the  depth  of  cut  must  be 


208  MILLWRIGHTING 

varied  to  make  up  for  any  thickness  or  thinness  from  the  5  7/16 
or  6%-inch  "reach,"  as  laid  down  in  the  lists  and  on  the  shaft 
drawing. 

Where  there  is  lateral  adjustment  in  the  pillow-blocks,  they 
may  all  be  cut-in  with  each  end  equi-distant  from  the  center  line  a, 
but  where  there  is  no  lateral  adjustment  it  is  the  practise  of  some 
millwrights  to  cut  the  block-seat  e  f,  Fig.  85,  a  little  longer  than 
the  pillow-block  and  to  fit  in  a  wedge  at  either  end  of  the  cast- 
ing. By  driving  or  slacking  these  wedges,  a  lateral  adjustment 
is  obtained.  It  is  the  usual  practise  of  the  writer  to  cut  in  the 
pillow-blocks  with  the  centers  of  the  bearings  dead  on  the  line, 
and  never  to  allow  for  wedges  until  in  re-alining  the  shaft  after 
the  factory  has  been  run  a  little.  Then,  if  necessary,  the  ends  may 
be  cut  out  to  allow  movement  to  the  pillow-block  and  wedges  put 
in  as  found  necessary.  Wedges  work  loose,  therefore,  do  not 
put  them  in  unless  they  are  necessary. 

Rub  the  pillow-block  casting  back  and  forth  on  the  wood  and 
note  how  much  of  a  bearing  it  has.  Sometimes  a  few  minutes' 
work  with  a  cold-chisel  will  remove  a  lump  or  two  from  the 
casting  which  will  allow  a  much  better  bearing  on  the  bridge-tree. 
If  there  is  not  much  rust  on  the  bottom  of  the  casting,  a  little 
blue  or  red  chalk  rubbed  on  before  the  casting  is  rubbed  on  the 
wood  will  show  plainly  where  iron  or  wood  ought  to  be  removed. 

BORING  BOLT  HOLES. 

It  is  very  necessary  that  the  bolt-holes  should  be  bored  fair 
with  the  holes  in  the  castings,  and  nothing  is  more  aggravating 
than  being  unable  to  square  the  pillow-block  with  the  line  because 
of  a  badly  bored  hole  which  will  not  let  the  casting  twist  into 
place  by  %  inch  or  so.  To  properly  bore  holes,  mark  carefully 
after  the  pillow-block  has  been  fitted  in  place,  then  move  the  block 
to  one  side  and  bore  the  holes  carefully,  taking  pains  to  get  them 
plumb  in  both  directions. 

It  is  quite  easy  for  a  good  workman  to  bore  a  hole  perpen- 
dicular to  (square  with)  a  timber,  as  shown  by  Fig.  86,  but  it  is 
quite  a  task  to  make  the  bit  stand  true  with  the  timber  in  two 
directions.  An  experienced  mechanic  can  come  pretty  close  to 
it,  but  it  is  better  to  use  some  simple  mechanical  aid  which  renders 
it  very  easy  to  bore  all  the  holes  square  with  the  timber. 


LAYING  OUT  SHAFTING 


209 


When  a  man  stands  beside  a  timber  and  bores  a  hole,  it  is 
very  easy  to  hold  the  anger  a  pretty  square  wth  the  timber  in  a 
direction  lengthwise  of  the  stick,  but  just  how  the  auger  stands  in 
the  direction  b  c  the  workman  has  no  means  of  knowing.  The 
invariable  tendency  is  to  lean  the  tool  toward  the  workman. 
Thus  the  man  would  hold  the  auger  about  on  the  dotted  line  b. 
If  the  workman  should  stand  on  the  right  hand  of  the  timber  he 
would  invariably  incline  the  top  of  the  tool  in  the  direction  c. 

Should  the  workman  stand  straddle  of  the  timber,  then  the 
auger  would  be  "square"  enough  crosswise  of  the  timber,  but  it 
would  tip  toward  the  workman  as  shown  at  d.  Should  he  step 


FIG.    86.— BORING   "STRAIGHT"    BOLT   HOLES. 

to  one  side  of  the  timber  he  could  square  up  the  auger  as  shown 
by  the  dotted  line.  The  experienced  workman  who  wishes  to  bore 
a  very  true  hole  will  thus  step  to  one  side  a  couple  of  times  after 
the  worm  of  the  auger  has  fully  entered  the  wood  and  the  tool 
will  stand  alone.  By  thus  taking  a  look  at  the  tool  two  or  three 
times  at  an  angle  of  90  degrees,  the  auger  can  be  made  to  start 
right,  and  all  the  workman  has  to  do  is  to  keep  the  tool  from 
swaying  sidewise  in  either  direction  in  order  to  bore  the  hole 
fairly  accurate  in  both  directions. 

Sometimes  it  is  necessary  to  bore  through  thick  timbers  from 
the  opposite  side  from  which  the  holes  are  laid  out.  In  case  of 
confined  quarters  above  a  bridge-tree,  or  when  some  machine 
stands  close  above  the  pillow-block,  it  becomes  almost  a  necessity 


210  MILLWRIGHTING 

to  bore  up  through  the  timber  from  the  under  side  and  the  holes 
must  hit  those  in  the  pillow-block  fair  and  square. 

A  method  whereby  accurate  ranging-  of  holes  may  be  done  is 
shown  at  /  where  a  piece  of  board  with  a  straight  edge  is  nailed 
to  the  timber  and  carefully  ranged  in  the  exact  direction  the  hole 
must  point.  In  cases  of  angle  boring,  where  great  accuracy  is 
required,  two  pieces  of  board  at  right  angles  to  each  other  may 
be  nailed  on  and  the  auger  is  easily  ranged  in  two  directions. 

Frequently  a  good  mechanic  will  use  a  common  try-square 
for  plumbing  an  auger,  the  square  being  placed  on  the  timber  as 
shown  at  g.  Sometimes  the  square  is  used  alone,  again  it  will 
be  used  in  connection  with  the  ranging  target  /,  and  sometimes  the 
square  alone  is  used  lengthwise  of  the  timber  to  plumb  the  auger 
to  and  from  the  workman,  while  he  sets  the  auger  in  the  other 
direction  by  his  eye. 

BITS  AND  AUGERS. 

Of  all  the  known  tools  for  making  holes  in  wood,  probably 
there  are  none  better  than  the  time-honored  "ship  augers,"  as 
shown  by  Fig.  86  at  a,  d,  and  h.  These  tools  will  cut  faster,  last 
longer  and  do  better  work  than  any  other  form  of  bit  known  to  the 
trade.  The  "ship  auger"  is  a  single-thread  tool,  the  chip-con- 
veying screw  being  very  heavy  and  the  outside  bearing  upon  the 
work  being  wide  and  strong.  This  form  of  bit  usually  comes  with 
a  plain  shank  upon  which  the  blacksmith  will  weld  the  double 
handle  shown  by  the  engraving.  The  single-screw  bit  above 
described  will  not  follow  the  grain  readily,  and  if  the  worm  be  filed 
off  the  bit  will  bore  absolutely  straight  in  the  direction  it  is  started, 
irrespective  of  the  grain  of  the  timber,  or  of  holes,  knots,  etc. 

While  the  "Jennings"  bit  is  the  standard  of  today,  there  is  a 
single-lip  bit  in  the  market  which  has  a  central  shaft  or  spindle 
extending  from  shank  to  cutting  edge,  thus  making  the  bit  very 
stiff.  The  twist  of  this  bit  increases  in  pitch  from  cutting  lip  to 
shank,  thereby  sending  the  chips  out  "faster  than  they  are  cut" 
and  preventing  clogging  to  a  great  extent  when  the  bit  is  buried 
over  the  twist  in  the  toughest  kind  of  wood.  This  bit  is  capable 
of  doing  a  good  deal  of  hard  rough  work,  and  it  also  cuts  as 
smooth  a  hole,  if  not  the  smoothest  of  any  bit  in  the  market.  It 
lacks  in  one  thing,  and  that  is  the  "nail-resisting"  power,  for,  like 


LAYING  OUT  SHAFTING  211 

the  curved-lip  bit,  it  goes  all  to  pieces  when  run  against  a  nail. 
It  lacks  the  useful  property  of  being  readily  filed  into  shape  after 
being  dulled  that  is  possessed  by  the  Jennings  and  the  "ship-auger" 
bits.  These  bits  are  illustrated  by  Fig.  140,  on  page  368. 


CHAPTER  XII. 

PUTTING  PULLEYS  IN  PLACE. 

A  few  years  since,  there  was  considerable  said  in  regard  to  the 
manner  in  which  curved-arm  pulleys  should  be  placed  upon  a 
shaft.  The  pulleys  had  their  arms  made  curving  because  the  laws 
of  rim  and  arm  proportion  was  not  as  well  understood  then  as 
now,  and  with  a  thin  rim  which  set  quickly  and  left  thick  arms 
projecting  from  a  thin  hub,  the  hub  and  rim  cooled  first,  then 
when  the  arms  cooled  down  and  contracted,  and  as  there  was 
nothing  which  could  yield  to  the  heavy  strain,  the  arms  were 
pulled  apart  or  separated  from  the  rim  or  from  the  hub.  To 
remedy  this,  the  arms  were  curved  so  that  when  they  contracted 
in  length  the  hub  twisted  around  a  little  but  the  arms  did  not 
break  off. 

A  lot  of  nonsense  was  in  circulation  about  so  placing  the 
pulley  that  the  belt  pull  would  place  the  arm-metal  in  compression 
instead  of  in  tension,  just  as  if  a  few  pounds  of  belt  pull  would 
ever  find  whether  the  metal  was  in  compression  or  in  tension. 
Pulleys  are  nearly  all  made  with  straight  arms  nowadays,  the 
rims,  arms  and  hubs  are  proportioned  right,  and  nothing  breaks. 
The  .only  thing  the  millwright  should  look  after  when  placing 
a  pulley  is  the  way  the  key  must  drive  in  order  to  sometime 
permit  the  pulley  to  be  taken  off  the  shaft  again. 

When  plenty  of  hoisting  tackle  is  at  hand,  the  problem  of 
getting  heavy  pulleys  into  place  is  comparatively  simple,  as  it  is 
only  necessary  to  hang  up  the  tackle  and  raise  the  pulley  into 
place,  slip  the  shaft  through  and  drive  the  key.  But  when  there 
is  no  tackle  at  hand,  resource  must  be  had  to  the  timber  pile.  A 
modification  of  the  "rocking-horse"  method  is  shown  by  Fig. 
87,  where  a  runway  is  rigged  for  the  pulley  to  be  rolled  up  an 
inclined  plane  until  it  is  at  about  the  required  hight. 

Then  the  pulley  is  chocked  by  two  pieces  of  timber  and  bits 
of  board  are  nailed  to  the  runway  plank  to  prevent  the  pulley 

212 


PUTTING  PULLEYS  IN  PLACE  213 

from  getting  away  during  subsequent  operations.  It  has  always 
been  the  practise  of  the  writer,  when  the  pulley  arrived  at  the 
position  shown  by  Fig.  87,  to  put  a  chain  or  a  heavy  rope  around 
the  rim  of  the  pulley  at  its  highest  point  and  have  that  chain 
made  fast  to  some  convenient  timber  overhead.  Then,  should 
anything  happen  to  the  blocking,  the  pulley  is  going  to  stay  where 
it  was  placed  and  not  slide  down  upon  people's  heads. 


/ 


FIG.   87.— PUTTING  ON  A   PULLEY  WITHOUT  HOISTING  TACKLE. 

Block  the  timber  a  to  prevent  its  possible  movement  toward  b, 
then  raise  the  end  of  the  runway  at  c,  and  insert  wedges  or  other 
blocking  at  d  to  bring  the  pulley  to  the  exact  hight  required. 
Some  more  wedges  at  e  e  and  /  allow  a  little  forward  and  back 
movement  to  bring  the  pulley  fair  with  the  end  of  the  shaft 
which  is  then  twisted  through  the  pulley  and  the  blocking 
removed. 


214 


MILLWRIGHTING 


LINING  UP  PULLEYS. 

Some  millwrights  stretch  a  line  across  the  sides  of. a  pair  of 
pulleys  and  then  move  one  or  both  until  the  sides  coincide  with 
each  other.  This  is  hardly  necessary,  as  a  pair  of  pulleys  can  be 
1  'sighted"  into  line  with  as  great,  if  not  greater  accuracy  than 
they  can  be  placed  by  means  of  a  string.  Simply  "squint"  past 
the  side  of  one  of  the  pulleys,  as  close  to  the  shaft  as  convenient, 
and  bring  the  edge  of  the  rim  of  the  sighted  pulley  fair  with 
the  one  over  which  you  are  sighting.  Then  sight  along  the  other 
sides  of  the  pulleys  and  see  if  they  come  even  also.  If  they  do, 
all  well  and  good.  If  not,  then  see  if  one  pulley  face  is  not  wider 
than  the  other.  In  case  such  be  the  fact,  divide  the  extra  width 
so  the  centers  of  the  pulleys  will  "track"  with  each  other. 


FITTING  KEYS. 

When  putting  keys  into  pulleys  see  that  they  do  not  bind 
on  top.  They  should  be  a  good  fit  and  move  easily  yet  snugly 
in  the  slot  in  both  shaft  and  pulley.  All  the  fit  or  the  holding 
pressure  must  be  between  the  sides  of  the  slots  in  pulley  and 
in  shaft.  A  set  of  double  calipers  is  very  convenient  when  fitting 
or  making  keys,  though  two  ordinary  sets 
may  be  used  instead  of  the  double  tool,  one 
form  of  which  is  shown  by  Fig.  88  and  can 
be  easily  made,  being  simply  three  pieces  of 
sheet  iron,  about  1/16  inch  thick,  cut  out  as 
shown  and  fastened  together  with  two  ^4-inch 
rivets.  The  length  of  the  tool  is  about  eight 
inches.  Some  mechanics  prefer  to  let  the  cen- 
tral portion  run  upward  a  couple  of  inches  to 
form  a  holding  piece  by  which  the  tool  is 
grasped  between  the  thumb  and  fingers  when 
in  use. 

In  use  this  tool  is  set  to  the  thickness  of  the 

key  or  spline  (the  two  terms  have  the  same  meaning  and  are  used 
indiscriminately)  at  the  ends  of  that  article.  In  forging,  the 
smith  works  to  the  two  calipers  for  the  heel  and  toe  of  the  key, 
and  uses  the  larger  dimension  for  the  width  of  the  key  as  well 
as  for  its  thickness.  It  is  best,  however,  when  keys  have  to  be 


FIG.  88.— DOUBLE 
CALIPERS. 


PUTTING  PULLEYS  IN  PLACE  215 

made  in  any  quantity,  to  procure  some  steel  cold-rolled  to  the 
width  and  thickness  desired,  then  plane  the  toe  to  the  required 
thickness  and  the  key  is  done  with  no  expediture  of  time  at  the 
forge  or  at  the  vise.  The  shaper,  with  a  special  clamp  in  the 
vise-chuck  belonging  to  that  tool,  will  make  a  key  quickly. 

In  using  such  an  arrangement,  it  is  only  necessary  to  slide  the 
blank  be  it  narrow  or  wide,  thick  or  thin,  into  the  inclined  vise, 
which  is  set  to  key-taper  of  3/16  inch  to  the  foot,  and  plane  away 
until  the  point  or  toe  of  the  key  is  brought  to  the  required  thickness. 
It  is  very  little  work  to  make  keys  in  this  manner  and  it  costs  less 
than  forging  them  from  a  bar  of  any  size  which  comes  to  hand.  In 
fitting  the  keys,  after  forging  or  planing,  there  is  nothing  to  do  but 
to  drive  the  key  into  place  and  drive  it  out  again,  riling  off  the 
spots  where  the  key  rubs  hard  against  the  pulley  hub.  Some  of 
the  old-time  millwrights  "hot-fit"  keys.  The  blank  is  forged  as 
closely  as  possible,  then  it  is  driven  into  place  as  far  as  it  will  go, 
the  driving  being  done  as  quickly  as  possible  so  as  to  shape  the  key 
before  it  cools. 

After  heating  and  driving  a  couple  of  times  in  this  manner, 
the  taper  obtained  is  carried  along  the  blank  for  the  required 
length  of  key  by  forging  and  filing,  then  the  key  is  driven  cold 
and  fitted  by  further  filing  as  found  necessary.  The  great  objec- 
tion to  the  hot  fitting  method  is  its  unmechanical  features,  and 
the  possibility  of  upsetting  the  hot  key  in  a  chambered  hub.  The 
writer  had  that  experience  once  and  it  was  enough  for  a  life- 
time. That  crippled  key  would  not  come  out  and  to  the  best 
of  the  writer's  knowledge  and  belief  it  never  did  come  out ! 

MAKING  KEYS  ON  THE  JOB. 

When  keys  have  to  be  made  on  the  job,  it  is  as  good  a  way 
as  any  to  make  a  soft  wood  pattern  of  the  key  and  make  the 
pattern  fit  by  trying  it  into  the  key-seat  when  the  pulley  is  in 
place.  Fit  the  large  end  of  the  pattern  first  so  the  big  end  of  the 
key  will  barely  squeeze  into  the  keyway  with  the  pattern  reversed 
one  end  for  the  other.  Then  do  the  same  with  the  small  end  of 
the  pattern,  reversing  that  and  applying  it  to  the  outer  end  of 
the  keyway.  Plane  this  end  of  the  pattern  until  it  will  barely  force 
into  the  keyway.  Then  it  is  an  easy  matter  to  plane  a  straight  slant 
between  the  two  fitted  ends  of  the  pattern,  and  but  very  little 
more  fitting  of  the  pattern  will  be  required. 


216  MILLWRIGHTING 

•  SET-SCREWS. 

The  conventional  pulley  fastenings  are  keys  and  set-screws 
if  the  clamp  devices  of  some  of  the  wooden  and  other  split  pulleys 
be  excepted.  But  there  is  at  present  no  way  of  holding  a  pulley 
in  place  under  heavy  loads  which  works  as  well  as  the  well-fitted 
key.  The  set-screw  answers  very  well  where  there  is  little  power 
to  be  transmitted,  but  it  will  not  do  for  real  heavy  work.  The 
various  clamp-hub  devices  put  out  by  the  makers  of  light  wooden 
and  metal  split  pulleys  answer  very  well  where  set-screws  will 
do  the  work. 

These  same  pulley  makers  have  found  it  necessary  to  provide 
forms  of  hubs  which  can  be  key-seated,  thus  acknowledging  by 
their  own  products  the  unanswerable  argument  that  nothing 
holds  a  pulley  under  heavy  torsion  strain  except  a  well-fitted 
key.  And  here  it  comes  right  down  to  a  question  of  shear,  as 
discussed  on  page  186. 

There  must  be  provided  such  a  quantity  of  metal  in  single 
shear  that  the  torsional  moment  will  not  shear  that  amount  of 
metal  between  the  pulley  hub  and  the  shaft.  This  is  where  the 
set-screw  fails  after  it  has  been  drilled  into  the  shaft.  There  is 
so  great  a  torsional  moment  that  the  two  surfaces  mentioned  act 
as  wire  cutters  and  shear  the  set-screw  cleanly  in  two.  Or  if 
the  screw  be  not  let  into  the  shaft  enough  to  be  cut  off,  the  shear- 
ing strain  drags  the  point  of  the  screw  around  the  shaft,  this 
time  shearing  the  metal  of  the  shaft  instead  of  that  in  the  pin. 

SHEAR  IN   SET-SCREWS. 

The  millwright  can  easily  figure  the  amount  of  strain  existing 
in  key  or  set-screw  between  the  shaft  and  hub,  and  he  can  also 
determine  that  the  set-screw  can  be  made  large  enough  to  safely 
carry  all  the  strains  at  the  point  mentioned.  But  when  he  ascer- 
tains that  the  size  of  set-screw  required  will  nearly  cut  the  shaft 
in  two  when  drilled  into  it,  then  it  is  seen  that  some  other  way 
of  obtaining  the  necessary  shear-section  must  be  used  because  it 
cannot  find  room  in  the  shape  of  a  screw. 

Fig.  89  shows  the  comparative  holding  power  of  set-screws 
and  keys,  and  in  that  engraving,  assuming  it  to  show  a  piece  of 
2-inch  shaft  (1  15/16  inches)  the  key  will  be  made  i/>  inch  wide 
and  it  is  cut  into  the  shaft  %  inch.  Supposing  that  the  torsional 


PUTTING  PULLEYS  IN  PLACE 


217 


strain  be  great  enough  to  shear  the  shaft  along  the  broken  line 
a,  which,  in  a  hub  4  inches  long  on  a  2-inch  shaft,  would  give  a 
section  for  the  shear  of  about  y±X^  inches=l  square  inch  of 
metal.  But  it  is  impossible  for  the  metal  to  shear  at  the  line  a. 
Even  should  the  piece  be  loose  above  the  break  line  the  shaft 
could  not  turn  around  in  the  hub  because  of  the  wedge-like  action 
of  the  key  which  rides  up  on  the  flat  surface  of  the  key-seat, 
and  the  entire  section  of  shaft  along  the  line  b  must  shear  off 
before  the  hub  can  revolve  on  the  shaft. 

Thus  it  is  the  key  which  must  be  sheared  off  to  allow  the  shaft 
to  revolve,  since  it  has  been  shown  that  the  shaft  cannot  be 
sheared  so  the  key  will  not  hold.  The  key  has  a  section  along  the 
line  of  shear  of  %X4  inches=2  square  inches  of  steel,  corre- 


FIG.    89.— HOLDING  POWER  OF   SET-SCREWS  AND   KEYS. 

sponding  to  a  set-screw  1  3/5  inches  in  diameter,  the  size  of  screw 
shown  at  d.  Thus  it  is  no  wonder  that  set-screws  fail  to'  drive 
heavy  loads.  It  is  not  the  fault  of  the  set-screw,  for  that  is 
doing  all  it  can.  The  millwright  should  figure  this  matter  a  little 
when  he  is  tempted  to  trust  to  a  set-screw  to  drive  some  pulley — 
just  figure  the  torsional  moment  and  ascertain  just  what  the  fas- 
tening has  to  do,  then  decide  whether  "boy  set-screw"  is  able  to 
do  the  work,  or  whether  a  "man's-size"  key  is  not  necessary  in 
that  particular  instance.  Too  much  guess  work  in  set-screws 
and  pins  often  leads  to  trouble. 

The  only  place  where  set-screws  amount  to  much  is  when 
they  are  placed  on  top  of  straight  keys  and  serve  merely  to  hold 
the  pulley  from  slipping  sidewise  along  the  shaft.  The  combina- 
tion of  straight  key  and  one  or  two  set-screws  is  a  very  good  one 
and  has  been  adopted  by  some  large  manufacturers  of  power 


218  MILLWRIGHTING 

transmission  machinery  who  send  out  all  their  work  with  straight 
keys  and  set-screws  in  each  pulley. 

One  trouble  met  with  in  the  above  noted  method  of  fastening 
pulleys  is  the  tendency  of  the  keys  to  work  out  endwise  whenever 
the  set-screws  become  a  little  loose.  This  action  is  prevented  by  the 
Woodruff  system  presented  by  Fig.  90.  In  this  method  or  sys- 
tem the  pulley  is  fitted  with  a  straight  seat,  no  taper  being  per- 
mitted, and  the  set-screw  is  placed  anywhere  except  on  the  key. 
It  may  be  at  right  angles  to  the  key,  or  anywhere  else,  as  long  as 
the  set-screw  is  not  put  in  the  key-seat  itself. 


FIG.  90.— THE  WOODRUFF  SYSTEM  OF  KEYING. 

The  key,  as  shown  at  a,  Fig.  90,  is  a  half  round  piece  of  flat 
steel  which  just  fills  the  cut  b,  made  in  the  shaft  by  means  of  a 
milling  cutter.  When  the  key  has  been  placed  in  the  circular  cut 
made  for  it,  the  pulley  is  slipped  endwise  over  the  key,  then  the 
set-screw  is  tightened  and  the  key  can  never  get  out  as  long  as 
it  is  covered  by  the  pulley  hub.  The  only  objection  to  this  method 
of  keying  seems  to  be  that  the  shaft  is  weakened  to  a  consider- 
able extent  by  the  deep  hole  cut  in  the  shaft.  Much  more  metal 
is  removed  from  the  shaft  cross  section  by  this  method  than  by 
the  usual  method  of  cutting  a  key-seat,  therefore  the  shaft  is  weak- 
ened in  exact  proportion  to  the  removal  of  metal  from  the  cross 
section  of  the  shaft. 

KEYWAYS  AND  STRAIGHT  SHAFTING. 

Steel  shafting  as  now  manufactured  is  prepared  for  use  in  two 
ways  known  as  "cold-rolled"  and  "cold-drawn."  The  names  indi- 
cate the  method  used  in  bringing  the  shafts  to  size,  and  some 
people  prefer  one  kind  and  some  another.  The  usual  complaint, 


PUTTING  PULLEYS  IN  PLACE 


219 


however,  seems  to  be  that  the  cold-drawn  shafting  does  not  readily 
withstand  key-seating,  the  cutting  away  of  the  skin  on  one  side 
of  a  shaft  causing  the  piece  thus  cut  to  spring  and  bend  in  a 
most  unbecoming  manner  to  the  despair  of  the  man  who  is  trying 
to  make  a  straight  shaft  of  that  material.  Thus  for  wooden  pul- 
leys and  compression  couplings,  where  the  work  is  all  of  a  light 
character,  the  cold-drawn  shafting  gives  satisfaction.  But  when 
this  shaft  is  cut  full  of  heavy  key-seats,  then  another  story  is 
sometimes  told. 

STRAIGHTENING  SHAFTING. 

Almost  all  shafting  must  be  straightened  after  being  key- 
seated  and  fitted  with  couplings  of  the  flange  variety,  and  often 
some  straightening  must  be  done  on  the  job.  In  the  absence  of 
a  screw-press,  though  a  jack-screw  may  sometimes  be  impressed 
to  do  service  in  that  direction,  a  very  good  job  can  be  done  by  a 
combination  of  weight-loading  and  peening  methods. 

A  shaft  needing  to  be  "sprung"  a  little  at  a  is  represented  by 


FIG.    91.— STRAIGHTENING    A    SHAFT. 

the  engraving,  Fig.  91,  in  position  to  be  straightened.  The  bend 
is  placed  on  the  steel  rail,  or  other  hard  bearing,  with  the  hollow 
side  of  the  shaft  uppermost,  although  it  is  shown  in  seemingly  the 
opposite  direction  in  Fig.  91,  for  the  reason  that  the  shaft  has  been 
loaded  with  the  pulley,  the  old  rail  c,  and  as  much  other  junk 
as  may  be  necessary  to  spring  the  ends  of  the  shaft  at  least  three 
inches  below  the  line  through  the  ends  of  the  shaft  and  bearing  a. 
Having  gotten  a  strain  on  the  shaft  in  the  direction  tending  to 
straighten  it,  but  with  much  less  pressure  than  is  necessary  to 
make  the  shaft  take  a  permanent  bend,  do  a  little  hammering  at 


220  MILLWRIGHTING 

d,  using  a  tool  made  somewhat  as  shown  at  e,  the  only  require- 
ment being  that  the  end  of  the  tool  which  bears  against  the  shaft 
is  hollowed  out  to  the  same  or  nearly  the  same  circle  as  the  shaft. 
This  is  to  prevent  the  shaft  from  being  flatted  or  otherwise  dis- 
torted by  the  hammer  blows  which  are  laid  upon  the  tool  with  a 
heavy  sledge,  as  shown  by  the  engraving. 

THEORY  OF  SHAFT  STRAIGHTENING. 

The  shaft  can  be  straightened  all  right  by  hammering  directly 
upon  its  surface,  but  it  is  apt  to  put  the  shaft  out  of  shape  at  that 
point  a  little,  which  may  be  avoided  by  using  the  tool  shown. at  e. 
The  theory  of  the  operation  is  that  with  a  strain  in  the  shaft  at  a 
the  hammering  at  d  stretches  the  metal  a  little,  thus  elongating 
that  side  of  the  shaft  and  straightening  it  a  little.  In  order  to 
determine  how  much  of  this  treatment  is  necessary  the  shaft  must 
be  unloaded  and  revolved,  either  between  centers,  or  otherwise 
supported  at  the  ends. 

The  loading  and  peening  operation  should  be  repeated  until 
the  shaft  has  become  as  straight  as  desired.  Great  accuracy  in 
straightening  may  be  obtained  in  this  way  by  repeated  and  careful 
peenings.  It  may  be  done  in  a  lathe  by  placing  the  hollow  part 
of  the  shaft  uppermost,  as  described ;  then  take  a  pry  over  some 
portion  of  the  carriage  with  a  lever,  and  when  a  strain  is  on  the 
shaft  have  another  man  do  a  little  peening  directly  above  the 
end  of  the  lever. 

Shaft  straightening  can  be  done  in  this  way  close  up  to  the 
shoulder  of  a  machine.  A  cutter-head  of  a  planer  may  thus  be 
straightened,  and  cutter-head  shafts  always  bend  in  the  corner, 
close  to  the  casting  to  which  the  knives  are  bolted — a  very  hard 
place  in  which  to  straighten  a  shaft  in  almost  any  other  manner. 
Be  careful  when  trying  the  above  described  method  and  do  not 
bend  the  shaft  too  much.  The  shaft  bends  much  easier  than  would 
be  expected,  and  the  inexperienced  workman  frequently  bends  the 
steel  too  much  the  first  time ;  therefore  go  slow  "until  you  get  the 
trade  learned." 

SETTING  UP  JOURNAL  BEARINGS. 

Before  proceeding  to  put  the  belts  on  the  pulleys  of  our  newly 
hung  shafting,  a  few  words  are  in  order  in  regafd  to  the  setting 


PUTTING  PULLEYS  IN  PLACE  221 

up  of  the  journal-bearings.  If  a  rigid  pillow-block  is  used,  there 
is  nothing  to  be  done  except  to  pack  under  the  cap  with  liners 
until  the  cap-bolts  can  be  screwed  down  tight.  Never  let  a  bear- 
ing go  when  the  cup  cannot  be  forced  down  to  a  solid  bearing 
without  binding  the  shaft.  Sometimes  the  liners  are  just  a  trifle 
too  thin,  and  the  temptation  is  great  to  pass  them  with  the  cap- 
bolts  set  back  just  a  little.  But  this  does  not  pay.  If  cap-bolts 
are  to  be  kept  tight  the  liners  must  be  thick  enough  so  the  nuts 
or  bolts  can  be  screwed  down  tight. 

Hardwood  makes  very  good  liners,  so  does  iron  or  soft  steel. 
Pine  is  not  good  for  this  purpose  unless  it  has  a  very  wide  bearing 
surface,  large  enough  to  stand  the  pressure  from  the  bolts  without 
flattening  out.  When  a  liner  squashes  down  in  a  bearing  it  is 
time  that  harder  material  be  used  in  place  of  the  soft  stuff.  Some 
concerns  send  out  bearings  in  which  the  liners  are  all  in  place  and 
of  just  the  right  thickness,  and  the  liners  themselves  are  made  of 
many  thicknesses  of  very  thin  wood.  When  it  is  necessary  to 
tighten  the  cap  a  little,  it  is  only  necessary  to  peel  off  one  of  the 
thin  layers  of  wood  from  each  liner — and  the  job  is  done. 

CAPILLARY  OILED  BEARINGS. 

Many  manufacturers  of  pillow-blocks  do  not  send  out  fitted 
liners  or  any  liners  at  all  for  that  matter.  They  evidently  go  by 
the  maxim,  "out  of  sight,  out  of  mind,"  and  let  the  millwright 
work  out  his  own  salvation — and  liners. 

In  setting  up  bearings  fitted  with  capillary  oiling  attachments 
— plain  "wick"  bearings,  to  cut  out  the  high-flown  scientific  talk — 
be  very  careful  to  keep  the  wick  in  place  while  putting  the  shaft 
down  against  the  lining  of  the  bearing.  A  bunch  of  wicking 
between  the  shaft  and  the  box-lining  does  not  conduce  to  a  level 
or  easy  running  shaft  after  the  cap  is  screwed  down  against  the 
shaft,  clamping  it  as  in  a  vise  against  the  bunch  of  hair-cloth 
which  forms  the  "capillary." 

RING-OILING  BEARINGS. 

The  same  thing  must  be  observed  when  putting  a  shaft  into 
ring-oiling  bearings.  The  ring  or  chain  in  such  bearings  is  very 
frail  and  is  easily  bent,  and  once  bent  the  oiling  of  that  bearing  is 
badly  damaged  if  not  entirely  knocked  out,  and  a  hot  box  will  be 


222  MILLWRIGHTING 

the  sure  result.  Another  thing  needs  close  attention :  Examine 
the  oil  cavity  closely  and  see  how  much  core  sand  there  is  adhering 
to  the  surfaces  of  the  metal  or  loose  in  the  bottom  of  the  oil  space. 
Sand  and  oil  is  a  pretty  good  mixture  to  keep  a  shaft  bright,  but  it 
is  not  good  for  lubricating  bearings,  and  it  is  the  unknown  cause 
of  many  a  hot  box  which  the  best  oil  in  the  world  will  not  keep 
cool. 

Make  sure  there  is  no  foreign  matter  in  any  of  the  oil  pockets. 
A  bit  of  wood  may  cause  serious  trouble  by  floating  on  top  of  the 
oil  when  the  cavity  is  filled,  getting  caught  in  the  ring  or  chain 
and  putting  the  whole  bearing  out  of  business.  A  three-inch  stub 
of  a  lead  pencil  put  one  whole  bearing  out  of  commission,  melted 
out  the  babbitt  lining  and  caused  nearly  a  whole  day's  shut  down 
of  the  entire  factory. 

When  the  bearings  were  set  up  and  made  ready  for  use,  the 
dude  bookkeeper  came  along  and  tried  to  sec  how  one  of  the  bear- 
ings was  rigged.  He  puggled  around  in  the  oil  cavity  with  his 
little  lead  pencil  until  it  slipped  out  of  his  fingers  and  went  down 
into  the  oil  cavity.  Then,  instead  of  telling  what  he  had  done, 
Mr.  Bookkeeper  quietly  slid  out  for  his  usual  daily  lunch — a  glass 
of  water  and  a  toothpick — and  let  the  pencil  go.  The  consequence 
was  a  very  hot  box,  so  hot  that  the  babbitt  melted. 

The  usual  oiling  arrangements  fitted  to  most  bearings  are  very 
defective  as  far  as  getting  the  oil  to  the  bearing  or  to  the  oil 
cavity  is  concerned.  The  big  grease  pocket  on  top  of  a  box  is  a 
fine  thing  to  catch  dust  and  sand  and  to  conduct  those  undesirable 
materials  directly  to  the  bearing  surface.  With  the  rigid  flat 
box,  so  much  used  on  elevating  and  conveying  machinery,  there  is 
absolutely  nothing  to  hold  the  oil  while  it  is  working  down 
through  the  very  small  oil  channel,  and  most  of  the  oil  is  lost  by 
being  spilled  on  the  outside  of  the  box. 

SPRING-COVER  GREASE  AND  OIL-CUPS. 

There  are  on  the  market  several  forms  of  nice  little  spring- 
cover  oil-cups  which  only  require  that  the  spout  of  the  oil-can 
be  pressed  against  them  to  cause  the  cover  to  be  moved  back  so 
that  oil  can  enter.  When  the  oil-can  spout  is  removed,  the  cup 
cover  springs  back  into  place  and  everything  is  closed  tight 
again.  Some  of  these  spring  cups  fit  a  pipe  thread,  and  others 


PUTTING  PULLEYS  IN  PLACE 


223 


are  made  to  be  driven  into  a  plain  hole,  being  held  there  by  fric- 
tion. They  are  very  desirable  for  light  machines  and  should  be 
used  wherever  frequent  oiling  is  necessary.  There  is  no  time 
lost  by  unscrewing  oil-cup  covers  when  these  cups  are  used, 
and  no  covers  are  lost  or  left  off  either. 

OIL-CAP  AND  NIPPLE  OILERS. 

For  lines  of  shafting,  elevating  and  conveying  machinery, 
and  in  fact  for  all  rough  bearings  which  are  exposed  to  dust,  and 
especially  where  the  owners  refuse  to  go  to  much  expense  for 
oiling  devices,  the  writer  has  obtained  first-rate  results  from  the 
simple  yet  effective  "oil^cap  and  nipple"  devices,  the  use  of  which 
was  specified  on  page  198.  These  little  appli- 
ances, as  shown  by  Fig.  92,  are  very  simple 
and  consist  of  two  short  pipes  or  nipples, 
from  %  to  y2  inch  in  diameter,  according  to 
the  size  of  pipe  tap  which  can  be  run  into 
the  oil-hole  provided  in  the  cap.  Sometimes  a 
%-inch  pipe  will  fill  the  hole.  At  other  times 
a  %-inch  pipe  will  be  found  necessary.  It 
may  suit  the  millwright  best  to  put  in  a 
reducer  when  a  large  tap  must  be  used  in  the 
cap,  then  a  uniform  size  of  pipe,  say  %  inch, 
may  be  used  throughout  the  job  for  oiling 
devices. 

Should  the  pipe  b  chance  to  be  %  inch  in 
diameter,  the  cover-pipe  a  will  be  y±  inch  in 
diameter.  When  the  hole  in  a  is  large,  then 
pipe  b  will  have  to  be  larger,  say  %  or  % 
inch,  and  the  cover  nipple  c  and  the  cap  d 
must  each  be  one  size  larger  in  order  that 
they  slide  easily  over  b.  To  oil  bearing  a, 
it  is  necessary  to  remove  c  and  d,  which  are 
screwed  together.  They  are  replaced  after  the  oil  has  been  put 
in  pipe  b. 

When  rigid  flat  boxes  are  used,  it  is  the  custom  of  the  writer 
to  pack  a  little  waste  very  loosely  in  pipe  b  close  to  the  lower  end 
of  that  pipe;  then  when  the  oil  is  poured  in  at  the  upper  end 
the  lubricant  is  caught  and  held  by  the  waste,  through  which 


FIG.  92.— "OIL-CAP' 
AND  NIPPLE. 


224  MILLWRIGHTING 

it  finds  its  way  very  slowly — so  slowly,  in  fact,  that  it  forms  a  sort 
of  continuous  oiling  business  which  is  a  great  improvement  over 
the  usual  method  of  open  oil  holes,  or  perhaps  fitted  with  pine 
plug  closures. 

GREASE-CUPS. 

All  slow  moving  shaft  bearings  should  be  fitted  with  compres- 
sion grease-cups  and  a  man  should  be  trained  in  the  use  of  such 
cups.  The  great  fault  with  the  untrained  man  is  that  he  forces 
too  much  grease  through  the  cups.  When  grease  begins  to  form 
ridges  just  outside  the  boxes  on  and  around  the  shaft,  then  it  is 
certain  that  too  much  grease  is  being  forced,  and  the  quantity 
should  be  cut  down  at  once.  But  a  very  small  fraction  of  a  turn 
at  the  grease-cup  cap  is  required  to  lubricate  the  bearing  of  a 
1  15/16-inch  shaft  for  a  day's  run. 

BALL-  AND  ROLLER-BEARINGS. 

The  great  decrease  in  friction  of  shaft  and  other  journals  by 
fitting  them  with  ball-  or  roller-bearings  is  not  only  due  to  the 
replacing  of  sliding  by  rolling  friction,  as  many  people  suppose, 
for  well  lubricated  journal-bearings  have  a  coefficient  of  friction 
of  0.09  to  0.15,  while  roller-bearings  show  coefficients  ranging 
from  0.01  to  0.03.  There  is  another  great  cause  of  friction 
decrease  on  account  of  the  roller-bearing,  and  that  is :  the  latter 
form  of  bearing  is  independent  to  a  large  extent  of  lubrication, 
and  the  fact  of  becoming  dry  does  not  increase  the  coefficient 
of  friction  as  it  does  with  plain  journal-bearings  where  sliding 
friction  must  be  accounted  for. 

Ball-bearings  are  equally  efficient  with  roller-bearings,  as 
friction  reducers,  but  the  great  trouble  with  the  ball-bearing  is 
that  there  is  not  sufficient  surface  to  carry  the  load,  therefore  the 
balls  wear  out  much  quicker  than  the  rolls.  Unfortunately, 
increasing  the  diameter  of  a  ball-bearing  does  not  increase  its 
bearing  surface  as  fast  as  it  increases  the  inconvenience  of  using 
the  larger  sizes,  hence  the  remedy  must  be  looked  for  in  some 
other  direction. 

If  a  ball-bearing  has  its  length  (if  such  a  term  can  be  per- 
mitted) increased  to  increase  the  bearing  surface,  then  the  ball 
thus  treated  becomes  a  roll,  and  the  transformation  into  the 


PUTTING  PULLEYS  IN  PLACE  225 

roller-bearings  is  complete.     Thus  a  roller-bearing  is  in  fact  a 
ball-bearing  with  elongated  balls. 

THE  SHORT  LIFE  OF  BALLS  IN  BEARINGS. 

When  bearings  are  mounted  upon  balls,  the  slight  surface  pre- 
sented, even  in  the  aggregate,  by  a  considerable  number  of  balls 
is  very  slight  indeed,  and  a  large  amount  of  wear  takes  place 
quickly,  hence  the  exceedingly  short  life  of  the  ball-bearing  when 
used  in  heavy  journals.  An  excellent  example  of  this  matter  is 
in  a  ball-thrust  bearing,  placed  against  the  end  of  a  shaft  in  a 
Jordan  beating-engine  in  a  paper  mill.  Before  the  thrust  bearing 
was  put  in  position,  the  thrust  was  carried  by  rings  on  the  shaft, 
and  the  steam  engine  indicated  90  horse-power. 

After  the  thrust-bearing  was  in  position,  the  thrust  rings  being 
left  as  they  were  and  the  new  bearing  arranged  to  take  the  strain, 
the  engine  indicator  card  figured  60  horse-power,  showing  a 
saving  of  30  h.p.,  or  33  1/3  per  cent.  But  the  balls  did  not  last 
long.  They  were  disposed  in  concentric  rows  around  the  center 
of  the  shaft,  and  placed  in  a  cage  so  that  their  relative  position 
must  always  be  maintained.  After  a  few  weeks'  run  it  was 
found  that  the  balls  nearest  the  center  of  the  shaft  remained 
nearly  the  original  diameter  (y2  inch)  but  the  balls  in  the  outer 
rows  were  reduced  greatly,  the  diameter  of  the  balls  in  the  outer 
circle  being  not  over  %  inch,  and  increasing  step  by  step  as  the 
rows  neared  the  center. 

While  this  bearing  was  a  success  in  saving  power,  it  was  a 
failure  after  all,  because  it  could  not  be  made  to  stand  up  under 
the  severe  pressures  put  upon  the  balls.  Had  the  design  of  the 
bearing  been  changed  so  as  to  permit  the  balls  to  be  placed  against 
the  original  thrust  rings,  there  is  no  doubt  but  the  device  would 
have  been  a  success. 

ROLLER-BEARINGS. 

High  grade  roller-bearings  are  regularly  on  the  market,  and 
are  made  by  several  concerns  manufacturing  them  exclusively. 
With  the  construction  of  these  the  millwright  has  little  to  do, 
but  upon  their  application  everything  depends,  as  far  as  the  saving 
of  power  and  the  life  of  the  bearing-  is  concerned.  When  a 
bearing  is  attached  to  a  shaft,  unless  great  care  is  taken  that  the 


226  MILLWRIGHTING 

race  or  shell  for  the  rolls  is  in  exact  line  with  the  shaft,  there 
will  be  unequal  wear  which  will  more  than  counteract  the  saving 
in  power  by  reduced  friction. 

The  surface  of  the  shaft  against  which  the  rollers  bear  must 
be  very  smooth  and  true.  It  must  be  as  perfectly  cylindrical  as  is 
possible  to  make  it,  and  the  presence  of  lumps,  holes,  etc.,  can  only 
go  to  add  to  the  coefficient  of  friction.  If  it  were  possible  to 
make  the  surfaces  of  the  rolls  and  of  their  housings  perfectly 
smooth  and  inelastic,  then  there  would  be  no  friction  whatever, 
and  were  it  not  for  the  resistance  of  the  air,  a  shaft  thus  mounted 
on  the  perfect  bearing  surfaces  would  continue  to  revolve  forever. 

But  as  we  can  never  make  perfect  surfaces,  and  cannot  remove 
the  air  resistance,  we  must  continue  to  roll  rough  surfaces  over 
each  other  and  to  pull  surfaces  against  the  air  resistance,  and  con- 
fine our  exertions  to  obtaining  the  best  possible  conditions.  There- 
fore make  the  roller  race  as  smooth  and  as  perfect  as  possible,  and 
make  the  rolls  themselves  perfectly  round  and  smooth,  and  make 
them  so  hard  that  they  will  not  change  shape  under  pressure,  yet 
they  must  be  very  elastic  lengthwise  in  order  that  they  may  con- 
form to  such  inequalities  as  may  get  into  the  roller  race  in  spite  of 
our  best  efforts  to  the  contrary. 

CARE  OF  ROLLER-BEARINGS. 

Once  roller-bearings  have  been  installed,  good  care  should  be 
taken  of  them.  It  is  a  mistake  to  suppose  that  a  roller-bearing, 
once  in  place,  will  run  forever  without  attention.  The  roller- 
bearing  must  be  taken  care  of.  It  must  be  kept  clean.  As  for 
lubrication,  some  people  claim  that  lubrication  is  not  necessary 
for  roller-bearings,  but  bear  in  mind  that  no  piece  of  machinery 
ever  built,  which  would  run  at  all,  would  not  run  better  when 
well  lubricated,  and  roller-bearings  are  no  exception. 

If  a  roller-bearing  is  to  be  neglected  and  never  looked  after, 
once  it  is  installed,  then  it  might  be  better  to  omit  lubrication  on 
the  grounds  that  the  dry  bearing  would  be  less  liable  to  clog  with 
dirt.  But  as  there  will  be  more  friction  at  the  ends  of  the  rolls 
without  oil,  it  certainly  will  pay  to  lubricate  the  bearing  and  then 
take  care  of  it.  When  rolls  once  slide,  be  it  ever  so  little,  they 
are  gone,  and  can  never  be  made  to  run  properly  again  without 
regrinding.  And  dirt  and  dry  surfaces  go  far  toward  making 
rolls  slip  instead  of  revolve. 


PUTTING  PULLEYS  IN  PLACE  227 

PIN  BEARINGS. 

There  is  a  form  of  roller-bearing  in  use  a  great  deal  in  cars 
which  are  to  be  used  on  the  floor  of  a  factory,  being  pushed  by 
hand  on  floor  or  on  track,  as  needed.  When  such  cars  are 
intended  to  carry  heavy  loads,  they  are  fitted  with  bearings  similar 
to  the  roller  type,  but  much  more  simple.  These  are  known  as 
"pin"  bearings  and  are  made  of  plain  short  pieces  of  cold-rolled 
steel  rod,  cut  to  length,  and  interposed  between  the  journal  and 
the  housing  of  the  bearing. 

When  making  rolls  of  this  kind,  it  is  only  necessary  to  select 
straight  and  round  pieces  of  rod,  saw  them  off  square,  and 
remove  the  corners  to  prevent  the  pins  from  catching  against  the 
end  of  the  race  and  "slewing"  around  more  or  less  diagonal  with 
the  bearing.  When  designing  a  pin  bearing,  it  is  evident  that 
there  must  be  a  certain  relation  between  the  number  of  the  pins, 
the  diameter  of  the  pins  and  the  diameter  of  the  journal. 

Should  the  millwright  have  occasion  to  design  a  pin  bearing 
(or  a  roller-bearing,  for  that  matter),  and  wish  to  ascertain 
the  number  of  pins  for  a  given  diameter  of  shaft,  or  the  size  and 
number  of  pins  to  fill  a  given  housing  upon  a  shaft  of  known 
diameter,  then  he  can  solve  the  problem  with  the  aid  of  the  simple 
formula  given  below  : 

The  diameter  of  the  circle  through  the  center  of  the  balls 
=diameter  of  a  ball  divided  by  the  sine  of  the  angle  occupied  by 
one-half  of  one  ball.  Putting  this  very  awkward  expression  into 
algebra,  and  letting 

N^number  of  balls, 

D—  diameter  of  circle  through  center  of  balls, 
d=diameter  of  balls, 
R=diameter  of  shaft, 


To  get  a  better  understanding  of  this  equation,  assume  that  a 
bearing  one  inch  in  diameter  is  to  have  six  balls  fitted  around  it. 
How  large  balls  will  be  needed? 

We  have  180  —  half  the  degrees  in  the  entire  circle  —  divided 
by  6,  the  number  of  balls,  gives  30  degrees  filled  by  one  of  the 
balls  in  a  half  circle,  this  of  course  being  equivalent  to  12  balls  in 


228 


MILLWRIGHTING 


a  whole  circle,  or  "one-half  the  angle  rilled  by  one  ball."  By 
looking  in  a  table  of  sines  in  Trautwine,  or  some  other  reference 
book,  it  will  be  found  that  the  sine  of  30  degrees  is  exactly  0.5, 


FIG.  93.— A  SIX-BALL  BEARING. 


or  one-half.  The  diameter  of  the  ball  being  1  inch,  and  the 
diameter  of  the  ball  circle  being  d-l-0.5,  or  y2>  it  is  evident  that 
the  ball  circle  is  just  twice  the  diameter  of  the  ball;  therefore 
the  balls  must  be  as  large  as  the  bearing  in  order  to  fill  the 
conditions  given  as  shown  by  Fig.  93. 


FIG.   94.— FINDING  THE  NUMBER  OF  BALLS  NECESSARY. 

Should  we  have  a  2-inch  bearing  and  a  3-inch  housing  and 
desire  to  ascertain  the  number  of  pins  required  to  fill,  we  may  use 
the  equation  as  follows,  the  layout  being  as  shown  by  Fig.  94. 


PUTTING  PULLEYS  IN  PLACE  229 

As  the  housing  is  1  inch  larger  than  the  shaft,  the  balls  must  be 
1/2  inch  in  diameter  (not  allowing  anything  for  clearance)  and 
the  ball  circle  will  be  2%  inches.  Hunting  up  all  the  numerical 
quantities  that  can  be  found,  we  obtain: 

N=? 

D=2i/2  inches, 
d=V^  inch. 

R=2  inches. 

Taking  the  formula  D= and  substituting  the  known  num- 

180° 
Sine— 

bers,    we    find    that    2.5=— — '•     This     reduces     to:     Sine     of 


180 
=0.2.     Looking  up  0.2   in  a  table   of  natural  sines,   it  is 

N 

found  that  0.2— Iiy2  degrees,  nearly.  Then  180-^11.5=15.65 
nearly,  therefore  15  pins  will  go  in,  and  if  they  are  a  little  smaller 
than  !/2-inch  in  order  to  give  the  necessary  clearance,  16  pins 
may  go  into  the  housing.  In  this  manner,  the  millwright  can  find 
any  of  the  quantities  pertaining  to  ball  or  roller  bearings,  provided 
a  sufficient  number  of  the  points  are  given. 

SET  COLLARS. 

Every  shaft  should  be  fitted  with  two  set  collars,  and  these 
should  preferably  be  placed  at  opposite  ends  of  the  same  bearing. 
It  is  the  practise  of  some  men  to  place  one  set  collar  at  either 
end  of  a  shaft,  but  the  two  collars  against  the  same  pillow-block 
is  preferable  as  it  leaves  but  one  bearing  to  look  to  in  case  the 
shaft  should  develop  too  much  end  motion.  In  very  long  shafts, 
the  variation  in  temperature  has  to  be  taken  into  account  when 
end  collars  are  used,  but  with  both  against  the  same  bearing, 
and  near  the  middle  of  the  shaft,  no  attention  need  be  given  to 
temperature  variations. 

Safety  set  collars  should  be  used  in  every  case,  and  no  collar 
with  a  set-screw  projecting  beyond  the  face  of  the  collar  should 
ever  be  tolerated.  Collars  are  now  generally  made  with  a  thin 
flange  at  either  end,  the  flanges  being  large  enough  to  project 


230  MILLWRIGHTING 

farther  than  the  head  of  the  set-screw,  thereby  preventing  flesh 
or  clothing  from  coming  in  contact  with  the  wicked  screw-head. 

Sometimes  it  is  possible  to  dispense  with  one  set  collar,  as 
one  or  more  of  the  pulleys  may  come  next  to  a  journal-bearing 
and  thus  take  the  place  of  a  collar  at  that  point.  When  setting 
up  counter  shafts,  see  that  there  is  a  collar  on  the  side  of  the 
loose  pulley  opposite  the  tight  pulley.  It  is  all  right  to  place  the 
tight  pulley  of  a  pair  next  to  a  bearing,  but  this  should  never  be 
done  with  a  loose  pulley,  unless  there  is  a  set  collar  between 
loose  pulley  and  the  journal-box  in  order  to  prevent  pinching  the 
pulley  between  the  tight  pulley  and  the  bearing. 

When  pulleys  are  thus  confined,  the  chafing  of  the  hub  against 
the  hub  of  the  tight  pulley  causes  undue  friction  at  that  point, 
which  frequently  causes  a  good  deal  of  heating,  burning  out  the 
oil,  and  helping  to  wear  out  the  loose  pulley  lining  or  bushing 
much  sooner  than  if  a  good  collar  had  been  placed  as  described. 

END  MOTION  TO  SHAFT. 

Never  collar  a  shaft  in  such  a  manner  that  it  cannot  have  a 
certain  amount  of  end  motion.  Any  shaft  or  machine  will  run 
better  in  its  bearings  if  a  certain  amount  of  end  motion  can  be 
permitted.  In  some  machines,  end  motion,  of  course,  cannot  be 
permitted  and  the  bearings  wear  out  all  the  sooner  for  it.  This 
is  true  in  circular  saws  and  similar  machines.  With  a  liberal 
allowance  of  end  motion,  the  particles  of  metal  in  box  or  bear- 
ing do  not  always  pass  each  other,  and  if  there  is  a  tendency  to 
wear  ridges  in  bearing  or  shaft,  end  motion  is  the  surest  preven- 
tative. 

Electric  generators  and  motors  should  always  be  given  1/16 
to  3/16  inches  end  motion  and  they  do  not  run  as  well  when 
tightly  collared.  Other  machinery,  shafting  included,  should  be 
given  a  similar  amount  of  end  motion  where  the  character  of  the 
device  will  permit.  In  some  kinds  of  machines,  an  oscillating 
movement  is  given  to  the  shaft  in  the  bearings,  particularly  in 
the  case  of  scrapers  which  act  upon  rolls  or  pulleys. 

THE  FINAL  ALINEMENT  AND  LEVEL  TEST. 

The  shafting  is  now  ready  to  receive  the  belts.  The  pulleys 
are  all  in  place,  firmly  keyed,  the  couplings  set  and  properly 


PUTTING  PULLEYS  IN  PLACE  231 

bolted,  and  all  the  journal-bearings  have  been  made  up,  the  caps 
tightened  solidly  upon  bottom  castings  or  liners,  and,  where  nec- 
essary, the  bearings  have  had  their  soft  metal  linings  scraped 
so  that  the  shaft  is  not  pinched  at  any  point.  In  fact,  the  42  feet 
of  shafting  and  its  ton  or  so  of  pulleys  revolve  so  easily  that  a 
man  can  turn  the  shaft  with  one  hand  applied  to  the  60  inches 
engine  pulley.  If  a  shaft,  after  full  adjustment,  will  not  turn 
as  easily  as  above  described,  something  is  wrong,  and  the  bear- 
ings should  be  investigated  again  before  the  belts  are  put  on. 

And  here  a  word  of  caution.  If  it  is  desired  that  all  the  belts 
shall  run  true  upon  their  pulleys,  without  running  off  an  inch  or 
so  on  one  side  or  the  other,  then  take  great  care  to  put  the  shafts 
exactly  level  and  as  parallel  with  each  other  as  it  is  possible  to 
make  them.  This  means  that  two  shafts,  each  10  feet  long,  are 
not  more  than  1/16  inch  farther  apart  at  one  end  than  at  the 
other,  and  that  upon  sighting  over  both  shafts  the  eye  can  detect 
not  the  slightest  variation  in  their  being  parallel. 

Sighting  over  shafts  is  not  a  good  way  to  make  them  parallel, 
but  it  is  a  first-class  check  on  what  has  been  done  with  transit 
and  station-rod,  and  the  sighting  should  never  be  omitted.  Sight- 
ing along  the  sides  of  pulleys  is  another  first-class  check  upon 
the  work  done  on  the  shafting,  and  by  thus  sighting,  the  mill- 
wright can  check  the  work  of  his  men  in  a  most  complete  and 
very  expeditious  manner.  But  in  thus  sighting  the  pulleys,  cau- 
tion must  be  observed  that  dependence  be  not  placed  upon  one 
sight  alone.  Two  sights  should  be  taken  over  every  pulley,  one 
sight  for  each,  as  indicated  in  Fig.  95,  where  a  and  b  represent 
two  pulleys  which  are  to  be  belt  connected  and  which  are 
expected  to  run  so  true  with  each  other  that  the  belt  will  show 
alike  on  each. 

DOUBLE  PULLEY-SIGHTING. 

With  the  eye  placed  at  c,  Fig.  95,  the  pulleys  a  and  b  appear 
to  be  in  line  with  each  other,  and  at  e  the  edge  of  the  pulley  b 
coincides  perfectly  with  the  entire  side  of  pulley  a.  But  if  the 
eye  be  directed  toward  the  top  portion  of  the  pulley,  say  at  f,  it 
will  be  seen  that  some  of  the  pulley  comes  in  view.  At  the  far 
side  of  the  pulley  g,  there  will  be  more  of  the  pulley  in  sight, 
showing  that  while  pulley  a  is  in  line  with  e,  that  pulley  b  is  not 


232  MILLWRIGHTING 

in  line  with  pulley  a,  as  may  be  proved  by  moving  the  eyes  to 
position  d,  which  is  in  line  with  the  opposite  face  of  pulley  b. 

When  the  conditions  are  met  with  as  in  Fig.  95,  it  is  time 
to  do  a  little  investigating  and  see  which  shaft  is  out  of  line — or 
which  pulley  is  not  true  upon  its  shaft.  First,  have  an  assistant 
revolve  pulley  (and  shaft)  a  slowly  while  you  continue  to  sight 
from  c.  If  no  variation  in  the  line  of  sight  is  observed  at  c ,  while 
pulley  a  revolves,  it  may  be  considered  that  pulley  a  is  all  right. 
Next,  have  pulley  b  revolved  slowly,  while  still  looking  from  a. 
If  no  variation  is  observed  at  e,  it  may  be  assumed  that  pulley 
b  is  also  truly  fixed  upon  its  shaft. 

But  should  there  be  observed  any  variation  of  side  of  pulley 
e  as  that  pulley  revolves,  then  try  line  of  sight  d,  and  have  pulley  b 
stopped  when  the  greatest  variation  is  either  to  the  right  or  to 
the  left,  and  look  at  the  pulley  to  see  whether  it  is  bored  too  large 

c>                                                                                                                                      Plf                fT 
sH  n  c       _____U 1 


FIG.    95.— DOUBLE-SIGHTING   OVER    PULLEYS. 

for  the  shaft  or  if  the  machinist  has  omitted  facing  the  sides 
of  the  pulley.  Occasionally  it  will  be  found  that  the  pulley  is  not 
bored  true  with  its  rim,  having  in  some  way  moved  in  the  boring 
mill.  In  such  cases,  two  courses  are  open :  Either  throw  away 
the  pulley  and  put  in  a  perfect  one,  or  place  the  points  of  varia- 
tion vertical,  and  then  sight  across  g,  e,  and  move  the  shaft  of 
pulley  b  until  the  sight  across  g,  e  coincides  with  sight  from  r. 
Previous  to  moving  shaft  through  b,  the  alinement  of  both 
shafts  should  be  tested,  for  there  is  a  possibility  that  the  shaft  at 
a  may  be  the  one  in  error,  in  which  case  shaft  b  should  not  be 
moved,  and  it  will  be  necessary  to  move  one  of  the  pulleys  along 
its  shaft  in  order  to  make  them  line  up  after  the  shafts  have  been 
placed  parallel.  With  pulleys  36  inches  in  diameter,  a  great 
degree  of  accuracy  can  be  obtained  by  sighting  pulleys  as  above 
— accuracy  not  only  in  alinement  of  the  pulleys,  but  provided 
the  pulleys  are  truly  finished  and  set  on  their  shafts,  accuracy 
in  the  alinement  of  the  shafts. 


PUTTING  PULLEYS  IN  PLACE  233 

A  FINAL  TRANSIT  TEST. 

Everything  being  found  properly  adjusted  while  sighting  the 
pulleys  as  above,  it  is  well  to  give  the  shafts  a  final  transit  test,  or 
failing  the  transit,  to  go  over  the  line  again  with  straight-edge  and 
spirit-level,  and  to  again  test  the  alinement  of  the  shaft  with  the 
targets  or  station  stones.  In  the  final  test,  to  be  described,  the 
same  method  should  be  followed  which  would  be  used  were  the 
shafting  to  be  overhauled  after  it  had  been  running  a  considerable 
length  of  time.  It  will  be  assumed  that  the  millwright  does  not 
know  the  condition  of  the  shafting,  and  desires  to  find  out  whether 
or  not  it  is  straight  and  level. 

Place  the  transit  on  the  station  stones  and  pick  up  the  shaft 
line,  or  take  up  that  line  from  whatever  targets  may  be  available 
for  that  purpose.  Replace  the  leveling-rod  head  on  its  rod,  or 
put  it  on  a  plain  piece  of  square  rod.  Place  the  free  end  of  the 
rod  against  the  shaft,  hold  the  rod  horizontal,  and  set  the  sliding 
head  to  a  sight  from  the  instrument  cross-hairs,  then  carry  the 
rod  to  the  next  bearing  and  test  the  shaft  at  that  point.  If  the 
cross-hairs  cut  the  same  point  on  the  rod,  that  portion  of  the 
shaft  is  O.  K.  Proceed  in  that  manner  to  each  bearing.  Where 
the  4  7/16-inch  shaft  is  encountered,  it  will  be  necessary  to 
shorten  the  rod  by  sliding  the  head  along  y±  inch,  and  when  the 
3  15/16-inch  shaft  is  arrived  at  again,  the  rod  must  be  restored 
to  its  original  length. 

Any  variation  found  at  any  of  the  bearings  must  be  corrected 
by  moving  the  bearings  at  which  any  variation  is  noted,  and 
moving  that  bearing  the  amount  indicated  by  the  cross-hairs  and 
the  rod  target.  To  level  the  shaft,  or  to  test  its.  level,  another 
tool  will  be  convenient,  or  an  addition  of  the  leveling-rod  shown 
by  Fig.  4.  An  outline  of  this  tool  is  shown  by  Fig.  96.  It  differs 
from  the  regular  leveling-rod  as  shown  by  Fig.  4  only  in  the  hook 
c,  which  is  screwed  into  the  end  of  rod  a  or  fastened  firmly  thereto 
in  any  convenient  manner. 

When  the  rod  is  in  use,  the  hook  c  is  placed  over  the  shaft, 
and  being  made  of  %-inch  soft  steel  it  can  be  placed  in  a  very 
narrow  space  between  pulley  and  hanger  or  hanger  and  collar. 
The  hook  should  be  so  shaped  that  the  rod  will  hang  in  a  vertical 
position,  thus  becoming  self-plumbing.  A  hole  is  bored  in  the 
sliding  head  &,  and  a  clip  of  some  sort  pushed  into  the  hole  to 


234 


MILLWRIGHTING 


support  the  bit  of  pipe  d,  capped  at  its  lower  end,  rilled  partly 
with  kerosene  oil  and  finished  with  a  wick  in  the  upped  end.  The 
little  torch  thus  provided  serves  to  light  the  sliding  head  so  that  a 
decent  sight  of  it  may  be  had  through  the  telescope.  A  candle 
may  be  used  in  place  of  the  torch,  but  as  that  keeps  getting  shorter 
it  is  not  quite  as  convenient  as  the  torch. 

When  the  leveling-rod  is  not  at  hand,  or  it  is  too  much  work 
to  rig  up  the  hook  c,  a  very  good  substitute  for  the  entire  rod 


I 


FIG.     96.— RODS    FOR    LEVELING 
SHAFTING. 


FIG.    97.— PLAIN    LEVELING    AND 
ALINING    RODS. 


may  be  made  by  bending  up  a  piece  of  round  steel  as  shown  at 
e,  a  rod  %  to  %-inch  may  be  used  as  at  hand.  A  common  set 
collar  at  /  answers  the  purpose  of  a  sliding  head,  and  the  torch 
carrier  is  drilled  into  the  same  collar.  The  sighting  is  done  at 
the  upper  edge  of  the  collar,  the  mark  g  showing  where  to  set 
the  collar  when  the  larger  length  of  shaft  is  met  up  with. 

The  writer  has  often  used  the  transit  for  both  alining  and 
leveling  when  nothing  but  a  bit  of  plain  stick  was  available, 
the  "button-hook"  rods  not  being  forthcoming  at  the  time  they 
were  needed.  Fig.  97  illustrates  the  manner  in  which  a  bit  of 
board,  %  inch  square,  is  used  without  any  heads  or  hooks. 


PUTTING  PULLEYS  IN  PLACE  235 

The  upper  end  of  the  vertical  stick  e  is  placed  against  the  shaft, 
either  under  or  over  as  the  case  may  require,  and  a  mark  c  is 
made  where  the  cross-hair  cuts  the  stick.  Another  mark,  1/4 
inch  above  the  first  mark,  is  made  for  use  on  the  large  section  of 
shaft.  The  stick  is  carried  from  one  bearing  to  another  and 
sighted  as  described,  an  assistant  holding  a  lantern,  if  necessary, 
so  the  mark  can  be  seen. 

For  alining  the  shaft,  the  stick  is  held  horizontally  as  shown 
at  /,  with  the  end  thus  marked  against  the  shaft.  A  transit  sight 
is  had  at  the  stick,  and  the  marks  at  h  show  where  the  cross- 
hair cuts  across  the  stick.  In  many  instances  it  is  not  easy  to 
see  the  rod  from  the  transit  station,  owing  to  the  bridge-trees  and 
other  timbers.  In  this  case,  run  a  fine  saw  into  the  stick  on  the 
marks  and  hang  a  plumb-bob,  as  shown,  sighting  at  the  plumb- 
line  g,  which  hangs  down  in  easy  sight  from  almost  any  transit 
position. 

TESTING  SHAFTS  WITHOUT  THE  TRANSIT. 

When  the  shaft  must  be  tested  without  the  use  of  the  transit 
or  other  telescope  instrument,  stretch  a  line  conveniently  above 
the  shaft  and  a  few  inches  to  one  side.  Hang  a  plumb-line 
opposite  the  point  to  be  tested,'  and  after  the  bob-line  has  come 
to  rest,  carefully  measure  from  the  line  to  the  shaft,  placing  a  bit 
of  thin  stick  against  the  shaft  and  marking  the  stick  where  the 
bob-line  hung  past  it.  Carry  the  stick  to  each  point  in  succession 
which  is  to  be  tested. 

To  test  the  level  of  the  shaft,  a  straight-edge  should  be  used 
and  placed  upon  two  distance  pieces  which  will  reach  from  the 
straight-edge,  when  placed  above  the  pulleys,  down  to  the  shaft. 
Three  men  are  needed  for  this  work,  two  to  hold  the  distance 
pieces  and  the  straight-edge,  the  other  men  to  work  the  car- 
penter's level  which  is  applied  to  the  straight-edge  as  directed 
for  leveling  foundations,  page  38.  The  bearings  are  to  be  raised 
or  lowered  as  indicated  by  the  level  and  straight-edge. 

It  is  a  common  occurrence  to  see  millwrights  apply  the  lev^l 
direct  to  the  shaft.  This  method  is  all  right  under  certain  condi- 
tions, but  there  are  times  when  it  is  not  to  be  depended  upon. 
Every  shaft  must  sag  a  little  between  supports,  and  if  the  level 
be  applied  near  one  of  the  bearings,  it  will  not  indicate  exactly 


236  MILLWRIGHTING 

the  same  as  when  applied  at  the  center  of  a  span.  Again,  where 
there  are  heavy  pulleys  a  few  inches  from'  a  bearing,  as  all  pul- 
leys should  be  placed,  and  the  level  is  applied  just  outside  of  the 
pulley,  it  is  not  once  in  a  hundred  times  but  what  there  will  be 
found  sufficient  deflection  in  the  shaft  to  lead  to  a  considerable 
error  when  the  shaft  is  used  as  a  straight-edge. 


CHAPTER  XIII. 

BELTS  AND  BELTING. 

The  shafting  described  in  the  previous  chapter,  together  with 
the  several  counter  shafts  and  machines,  are  supposed  to  be  in 
position,  ready  for  the  belts.  The  several  pulleys,  as  laid  down 
on  Fig.  81,  are  supposed  to  be  of  proper  face  width  to  carry  the 
required  amounts  of  power.  We  will  not  check  these,  as  that 
business  should  have  been  done  when  the  factory  was  first  laid 
out,  but  we  will  check  the  engine  belt  and  see  under  what  condi- 
tions that  appliance  will  have  to  work. 

It  is  required  to  transmit  100  h.p.  from  a  120-inch  pulley  run- 
ning 85  r.p.m.  This  corresponds  to  a  belt  speed  of  about  2670 
feet  a  minute.  One  hundred  h.p.  means  3,300,000  foot-pounds  a 
minute,  and  3,300,000-^-2670=1235  pounds  pull  on  the  belt. 
Allowing  20  inches  of  belt  width,  there  would  be  a  pull  of  1235 
-^-20=61.8  pounds  pull  to  the  inch  of  width.  This  is  a  bit  more 
load  than  called  for  by  the  rule  of  "40  pounds  to  the  inch  of 
belt  width"  as  stated  on  page  133,  chapter  VIII.  But  60  pounds 
to  the  inch  is  allowed  by  some  designers,  and  so  is  88  pounds,  but 
as  that  matter  has  been  settled  by  the  maker  of  the  engine  we  can 
do  nothing  with  it  at  this  stage  of  the  game.  In  fixing  the  width 
and  diameters  of  pulleys  in  other  parts  of  the  transmission,  the 
width  should  be  decided  by  the  method  above  described. 

But  it  is  a  good  deal  of  work  to  make  the  calculations  as 
above  for  each  and  every  pulley  we  may  have  to  deal  with 
throughout  the  mill,  and  a  table  or  diagram  can  be  easily  made 
which  will  show  at  a  glance  the  amount  of  power  any  belt  will 
transmit  under  40  pounds  to  the  inch  pull,  and  at  the  given  (200) 
number  of  revolutions. 

A  BELT- WIDTH  DIAGRAM.  ,)    .<   < 

In  making  up  a  diagram  to  fit  any  width  and  'diameter4' of 
pulley  the  millwright  will  do  well  to  look  up  the  following 
formula,  where 

237 


238 


MILLWRIGHTING 


H.P.=Horse-power  transmitted. 
W= Width  of  belt,  in  inches. 
D— Diameter  of  pulley,  inches. 
N=Number  of  re  volutions =200. 
P=Pull  on  1  inch  of  Belt  Width=40. 
7u=3.141 
Hp=WDJLN   P. 

"  12x33,000 
Thus  a  72-inch  pulley  running  200  r.p.m.  under  a  belt  pull  of 


40   pounds 


transmit 


1X72X3.141X200X40 
H.P.=—  -=4.56 


12X33,000 

h.p.  with  a  belt  1  inch  wide.     In  order  to  transmit  exactly  4  h.p., 
the  pulley  should  have  a  diameter  of  4X72-^4.56=63.1  inches. 


Width  in  Inches 

•J          10       11       \'l/  13        1'4         15       10  d   17 


ao  40 

Horse  Power 

FIG.    98.— LAYING    OUT    A    BELT-POWER    DIAGRAM. 

From  this  data,  the  millwright  can  construct  the  diagram  as 
follows : 

Draw  a  vertical  line,  as  at  a  b,  Fig.  98,  and  divide  it  into  equal 
parts,  each  part  representing  2  inches  of  pulley  diameter.  On  the 
point  representing  63.1,  draw  the  horizontal  line  c  d,  and  divide 
this  into  any  number  of  equal  parts,  each  one  of  which  will  repre- 
sent one  inch  in  belt-  or  pulley-face  width.  It  makes  no  difference 
to  what  scale  these  lines  are  drawn,  whether  they  are  to  the  same 
scale  or  not.  Any  convenient  scale  may  be  used  which  will  fit 
the  paper. 

At  the  bottom  of  line  a  b,  draw  the  horizontal  line  a  c,  and 
divide  this  into  equal  parts,  four  of  which  make  one  part  on  line 


BELTS  AND  BELTING  239 

c  d.  For  convenience,  the  same  scale  may  be  used  for  lines  a  e 
and  c  d,  dividing  a  e  into  small  parts  and  taking  four  of  these  parts 
of  each  division  on  c  d. 

The  use  of  the  table  can  now  be  tested.  What  power  will  a 
1-inch  belt  deliver  on  a  pulley  63.1  inches  in  diameter,  running  at 
the  stated  speed  and  pull  ?  Look  along  the  vertical  line  of  pulley 
diameters  and  at  63.1  follow  horizontally  to  the  point  indicating 
1  inch  of  belt-width,  which  is  at  /.  Follow  this  line  vertically 
downward  to  the  horse-power  line  a  e,  and  at  g  it  will  be  found 
that  line  /  g  passes  through  the  4-horse-power  mark,  hence  the  1- 
inch  belt  on  a  pulley  63.1  inches  in  diameter  is  good  for  4  horse- 
power. 

If  we  desire  to  find  the  power  of  a  belt  6  inches  wide  on  a 
48-inch  pulley,  draw  the  diagonal  a  i  from  6  inches  on  the  63.1 
line,  then  from  48  on  the  diameter  line ;  intersect  the  diagonal  a  i 
at  h,  then  drop  vertically  to  the  hors'e-power  line  where  is  found 
18  h.p.,  the  power  of  a  6-inch  belt  under  the  conditions  named. 
To  test  the  matter,  pass  along  on  the  48-inch  line  to  the  diagonal 
k  a,  drawn  from  the  12-inches  mark.  These  lines  intersect  at  /,, 
from  which  point  drop  to  the  h.p.  line  at  36,  which  is  just  twice 
18,  showing  that  the  principle  of  the  thing  is  correct. 

This  matter  may  be  still  further  tested  by  drawing  diagonal 
n  a  from  the  18-inch  belt  point,  intersecting  the  48-inch  pulley 
line  at  o,  and  falling  to  p,  where  is  found  54  h.p.,  which  is  in 
direct  ratio  with  the  18  and  36  h.p.  already  noted.  Should  it  be 
necessary  to  work  with  larger  pulleys  than  are  indicated  on  the 
diameter  line,  the  diagonals  may  be  extended  indefinitely,  as  shown 
at  k  q,  where  the  12-inch  belt  diagonal  is  run  out  to  intercept  the 
72-inch  pulley  line.  This  shows  56  h.p. 

From  the  points  obtained  in  the  diagram  shown  by  Fig.  98, 
the  millwright  may  construct  the  chart  complete  by  simply  draw- 
ing in  the  horizontal,  vertical  and  diagonal  lines,  working  at  all 
times  from  lines  a  b,  c  d,  and  a  e,  stopping  only  at  the  limit  of 
the  paper  or  the  pulleys  to  be  worked.  Fig.  99  shows  the  com- 
pleted diagram  or  chart,  and  all  possible  combinations  of  belts 
and  pulleys  may  be  taken  directly  from  it,  for  the  pull  and  speed 
named,  of  course. 

A  piece  of  cross-section  paper  is  very  convenient  for  the  lay- 
ing down  of  diagrams  of  this  kind,  and  that  paper  was  used  in 


240 


MILLWRIGHTING 


10    20    30    40    50    60    70    80    90   100   110   120   130   140   150   160 

Horse  Power 
FIG.   99.— PULLEY,   BELT  AND  HORSE-POWER  DIAGRAM. 

making  up  the  large  diagram  shown  by  Fig.  99.  To  enable  large 
pulleys  to  be  charted,  the  diagram  was  extended  at  the  top,  and 
instead  of  working  from  the  63.1  line,  that  quantity  was  doubled, 
making  it  126.2,  and  the  diagonals  were  drawn  from  that  line. 

'  USES  OF  THE  BELT  DIAGRAM. 

It  is  required  to  determine  the  width  of  belt  necessary  to 
transmit  18  h.p.  from  a  pulley  28  inches  in  diameter.  Run  up 
from  18,  taken  on  the  h.p.  line  at  the  bottom,  until  that  line  inter- 
sects with  the  horizontal  line  from  28  on  the  left.  At  the  inter- 
section of  these  two  lines,  a  diagonal  is  found,  which  when  fol- 
lowed to  its  upper  end  terminates  at  the  figures  10.  Thus  a 


BELTS  AND  BELTING  241 

10-inch  belt  is  required  to  do  the  work  under  the  given  conditions. 
To  find  the  power  of  the  belt  at  any  other  number  of  revolu- 
tions, -divide  the  power  obtained  from  the  diagram  by  200  and 
multiply  the  quotient  by  the  speed  at  which  the  belt  is  to  run. 
For  instance,  what  would  be  the  power  of  the  belt  above  described 
were  its  pulleys  running  at  175  r.p.m.  instead  of  200  ?  The  answer 
is  18-^-200X175=15.75  h.p. 


FINDING  THE  LENGTH  OF  BELTS. 

After  the  pulleys  are  erected,  the  best  way  of  obtaining  the 
length  of  a  belt  is  to  measure  it.  But  that  seemingly  simple  mat- 
ter is  easily  said  but  hard  to  do  with  any  accuracy.  If  a  string 
be  used  to  measure  around  the  pulleys,  it  is  apt  to  stretch  consid- 
ably  under  the  tension  necessary  to  tighten  the  cord  to  the  sag  at 
which  it  is  desired  to  run  the  belt.  Then  when  the  string  is  laid 
loosely  on  the  floor  beside  the  belt,  and  not  under  tension,  its 
length  may  be  anything  but  right  and  the  belt  is  apt  to  be  cut 
too  short. 

A  steel  tape  is  the  best  thing  for  use  when  measuring  around 
a  couple  of  pulleys.  An  ordinary  non-stretching  tape  line 
answers  fairly  well  and  is  far  ahead  of  a  string.  A  wire  answers 
well.  If  a  string  must  be  used,  try  to  remember  how  hard  was 
the  pull  exerted  on  it  when  taking  the  measurement,  and  put 
on  the  same  amount  of  pull  when  measuring  the  belt. 

In  either  case,  whether  the  belt  be  measured  by  a  steel  tape 
or  by  a  tensional  string,  there  should  be  made  some  allowance 
for  the  stretch  of  the  belt  when  placed  upon  the  pulleys.  It  is 
usual  to  allow  1/8  m°h  to  the  foot  for  the  stretch,  therefore  the 
belt  must  be  cut  short  1  inch  for  every  eight  feet  of  its  length. 
In  a  72-foot  belt,  it  would  be  cut  72-^8=9  inches  short  of  the 
string  measurement. 

But  the  question  of  belt  measurement  comes  up  before  the 
shafting  has  been  erected.  The  millwright  knows  that  two  shafts 
are  to  be  erected  with  18-foot  centers,  and  that  a  36  and  a  24-inch 
pulley  are  to  be  placed  upon  the  respective  shafts  and  connected 
by  a  belt  How  long  will  be  the  belt?  That  is  the  question  the 
millwright  is  required  to  accurately  answer  "p  d  q,"  for  the  belt 
must  be  ordered  at  once  without  delay. 


242 


MILLWRIGHTING 
LENGTH-OF-BELT  CHART. 


A  chart  or  diagram  may  be  constructed  v^ery  easily  from  which 
may  be  taken  instantly  the  length  of  belt  necessary  to  wrap  half 
way  around  each  of  a  pair  of  pulleys.  While  the  chart  does  not 
take  into  account  the  slight  difference  due  to  the  difference  in 
arcs  of  contact  of  belts  over  pulleys  of  unequal  diameter,  the 
error  thus  caused  is  very  slight,  and  is  only  a  very  few  inches 
in  extreme  cases  of  a  very  large  and  a  very  small  pulley. 


40 


40 


60 


FIG.    100.— LAYING  OUT  A  LENGTH-OF-BELT  CHART. 

For  instance,  should  it  be  necessary  to  belt  a  pair  of  80-inch 
pulleys  the  length  of  belt  taken  up  by  wrapping  half  way  around 
each  of  the  pulleys  will  equal  the  circumference  of  one  of  the 
pulleys,  and  this  is  80-^-12X3.141=20.93  feet;  so  close  that  we 
will  call  it  21  feet.  To  originate  the  chart  or  diagram,  draw  the 
line  a  d,  Fig.  100,  making  it  21  parts  long  by  any  convenient 
scale.  This  line  should  be  drawn  at  an  angle  of  45  degrees  with 
lines  a  b  and  a  c,  which  should  then  be  divided  into  80  equal 
spaces,  each  space  representing  1  inch  of  pulley  diameter. 

The  diagonal   line  a  d  should  also  be  divided,  but  into  21 


BELTS  AND  BELTING 


equal  parts,  each  part  representing  one  foot  of  belt.  Through 
these  points  the  lines  14,  15,  16,  etc.,  should  be  drawn  and  marked 
with  the  figures  mentioned,  commencing  at  a,  which  represents 
0,  the  next  division  1,  etc.,  the  last  division  21,  occurring  at  the 
intersection  of  lines  c  d  and  b  d. 

Numbers  on  Diagonals  give  Length  of  Belt  Wrapping  Pulleys 


1 

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JJ  50 
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FIG.    101.— LENGTH-OF-BELT    CHART. 


244  MILLWRIGHTING 

Tracing  out  the  lines  leading  from  60  to  60  it  is  found  that 
they  intersect  upon  the  main  diagonal  a  d,  and  that  the  point  of 
intersections  lies  between  cross  diagonals  15  and  16;  hence  the 
length  of  belt  necessary  to  wrap  half  around  two  60-inch  pulleys 
is  about  15  feet,  8  inches.  If  we  require  the  length  of  belt  wrap 
for  pulleys  60  and  70  inches  in  diameter,  we  find  the  lines  from 
those  figures  intersect  nearly  on  the  17  line,  at  some  distance  from 
diagonal  a  d,  but  this  makes  no  difference,  and  17  feet  may  be 
taken  as  the  length  of  wrapped  belt  on  pulleys  60  and  70  inches 
in  diameter. 

The  intersection  of  the  50  and  the  80-inch  pulley  lines  also 
falls  on  diagonal  17,  and  we  find  that  it  requires  as  much  belt  on 
pulleys  60  and  70  inches  in  diameter  as  it  does  on  two  pulleys 
50  and  80  inches. 

Having  arrived  at  the  method  of  constructing  this  chart,  it 
may  be  developed  for  all  pulleys  up  to  80  and  120  inches  as 
shown  by  Fig.  101.  The  method  of  using  is  as  follows :  What 
length  of  belt  will  be  required  to  connect  pulleys  36  and  48  inches 
in  diameter  on  shafts  19-foot  centers?  The  chart  shows  that 
pulleys  36  and  48  inches  'require  about  10  feet,  10  inches,  or  we 
will  call  it  11  feet,  of  belt.  Twice  the  distance  between  shafts 
is  38  feet.  Eleven  feet+38  feet=49  feet  of  belt  necessary  for  the 
purpose. 

SELECTING  BELTING. 

Probably  there  is  no  subject  which  proves  more  vexatious  to 
the  millwright  than  that  of  belting.  There  are  so  many  kinds 
of  material,  so  many  varieties  of  each  kind,  and  as  many  more 
grades  of  each  variety,  that  it  requires  a  wise  man  to  get  the  most 
for  his  money  when  buying  belts.  Most  people  have  a  prejudice 
in  favor  of  some  particular  material  for  belts,  either  leather,  rub- 
ber, or  cotton,  and  when  this  prejudice  is  a  deciding  factor  the 
millwright  has  only  to  determine  which  variety  and  which  grade 
to  select — and  that's  enough. 

The  points  which  should  be  looked  to  in  leather  belting  are 
the  length  of  lap — which  is  the  principal  determining  factor — 
and  the  appearance  of  the  surface.  The  weight  has  something  to 
do  with  a  selection,  and  the  requirements  are  that  belting  shall 
weigh  not  less  than  16  ounces  to  the  square  foot.  But  this 


BELTS  AND  BELTING  245 

specification,  which  is  particularly  required  by  the  U.  S.  Govern- 
ment, is  of  doubtful  value  on  account  of  the  facility  with  which 
leather  may  be  "stuffed"  with  oil  and  other  substances  to  give  it 
he  required  weight.  The  appearance  of  the  leather  is  the  best  indi- 
cation of  its  quality.  This  and  the  presence  of  the  middle  of  the 
back  in  each  strip — for  belts  more  than  ten  inches  wide — are  the 
factors  by  which  to  judge  a  leather  belt,  and  experience  is  the 
only  way  of  acquiring  a  knowledge  of  leather  so  as  to  judge  by  its 
appearance. 

REQUIREMENTS  OF  LEATHER  BELTING. 

The  principal  requirement,  as  stated  above,  is  the  length  of 
lap,  which  cannot  be  more  than  4  feet  6  inches  in  a  first-class 
belt.  In  fact,  the  mere  presence  of  a  piece  of  leather  longer 
than  the  stated  length  condemns  the  belt  to  second  quality.  The 
reason  is,  the  hide  of  an  ox  will  not  yield  a  strip  of  leather  more 
than  4  feet  6  inches  long  without  running  into  the  neck,  a  part 
of  the  hide  which  when  made  into  leather  will  surely  stretch  out 
of  shape  more  or  less.  Some  inferior  belts  may  be  found  with 
strips  of  leather,  'laps"  they  are  called,  as  much  as  nine  or  even 
ten  feet  long.  The  best  thing  these  belts  are  good  for  is  to  sell, 
and  the  belt  dealer  is  the  only  man  who  reaps  a  benefit  from  such 
belts — and  even  then  he  gets  the  name  among  his  patrons  of  sell- 
ing poor  belting ;  therefore  the  "rubber-neck"  belting  may  not  be 
a  benefit  even  to  the  dealer. 

One  concern  which  makes  leather  belting  uses  the  side  pieces 
for  making  what  they  call  "quarter-turn"  or  "reel"  belts.  These 
are  made  from  side  strips  cut  down  near  the  belly  and  they  are 
supposed  to  be  made  up  with  the  side  of  the  strips  which  were  cut 
off  toward  the  back,  all  laid  the  same  way;  that  is,  the  side  of 
each  strip  which  grew  nearest  the  back  of  the  ox  is  kept  on  the 
same  side  of  the  belt  all  the  length  of  the  made-up  strip.  When  a 
quarter-turn  belt  is  fitted  from  the  specially  prepared  belting, 
the  back  edge  is  so  placed  that  it  is  on  the  short  side  of  the  belt, 
and  the  belly  side  of  each  strip  of  belt,  which  side  is  naturally  the 
longest,  does  the  stretching  act  as  the  belt  passes  around  the  angu- 
larly placed  pulleys  upon  which  it  must  run.  Thus  the  "special" 
belt  for  quarter-turn  pulleys,  which  is  sometimes  sold  at  an 
advance  over  good  short  lap  belting,  is  really  an  inferior  product 


246  M1LLWRIGHTING 

which  should  really  be  sold  for  less  instead  of  for  more  than  good 
short  lap  middle-back  belting. 

SELECTING  RUBBER  BELTS. 

The  two  determining  qualities  in  rubber  belting  are  the  weight 
of  the  cotton  duck  from  which  the  belt  is  made  and  the  weight 
and  quality  of  the  supposedly  rubber  coating.  Rubber  is  becom- 
ing so  scarce  and  so  high  priced  that  hundreds  of  substitutes  are 
used  and  real  rubber  may  soon  become  exceedingly  scarce. 

Some  "rubber  substitutes"  have  the  bad  habit  of  peeling  from 
the  cotton  as  soon  as  the  belt  gets  to  working.  There  is  no  way 
which  the  writer  is  aware  of  by  which  it  may  be  determined 
whether  or  not  the  belt  will  peel  or  split.  The  only  way  is  to 
try  it,  and  buy  the  belting  under  a  guarantee  for  its  replacement 
if  it  splits  or  peels  under  fair  usage. 

But  in  this  matter  there  is  another  side  in  wliich  the  belt 
maker  should  be  protected.  Peeling  and  splitting  of  rubber  belts 
sometimes  take  place  when  real  rubber  is  used  and  the  belt  is 
first-class  in  every  way.  In  cases  like  these,  the  belt  maker  should 
be  protected  against  loading  the  belt  to  more  than  its  safe  work- 
ing tension.  It  has  already  been  stated  that  a  belt  which  is  not 
loaded  to  more  than  40  pounds  working  pressure  to  the  inch  of 
width  will  never  fail,  slip  or  break.  But  the  working  strain  is  not 
by  any  means  all  the  stress  that  comes  upon  a  belt.  A  careless 
workman  may  put  a  belt  on  its  pulleys  in  such  a  manner  that  it 
will  not  stand  up  under  40,  or  even  under  20  pounds  working  pull. 
In  fact,  a  belt  may  be  placed  upon  pulleys  so  tightly  laced  or 
otherwise  joined  that  it  will  not  stand  its  own  weight. 

The  determination  of  the  "lacing  stress"  in  belts  will  be  dis- 
cussed very  shortly,  and  is  mentioned  here  only  to  show  that  more 
belts  fail  on  account  of  too  tight  lacing  than  fail  on  account 
of  poor  material  being  used  in  their  making.  The  weight  of 
rubber  belts,  and  the  thickness  of  the  rubber  coating,  together 
with  the  weight  of  the  cotton  duck,  are  determining  factors  in 
selecting  belts  of  this  kind. 

IMPREGNATED  STITCHED  COTTON  BELTS. 

In  selecting  this  belt,  and  there  are  hundreds  of  varieites  and 
grades  to  be  selected  from,  there  is  no  way  of  ascertaining  the 


BELTS  AND  BELTING  247 

actual  worth  of  any  given  sample  of  belt,  unless  some  physical 
tests  are  resorted  to.  The  writer,  for  several  years  having  to  pur- 
chase much  Gandy  belting,  hit  upon  the  following  specifications 
which  all  bidders  were  required  to  submit,  and  the  purchaser 
could  thereby  make  a  selection  at  his  discretion.  This  avoided 
being  "pestered"  a  dozen  times  by  a  dozen  belt  salesmen,  all  very 
much  in  earnest,  and  each  one  selling  "the  best  belting  in  the 
world." 

DATA  REQUIRED  FOR  SELECTING  "GANDY"  BELTS. 

When  the  millwright  is  offered  several  dozen  samples  of 
stitched  cotton  belt,  he  may  proceed  to  examine  them  as  follows : 

THE  "PICK." 

Cut  the  stitches  in  a  portion  of  the  belt  sample  and  unfold  a 
piece  more  than  one  inch  square.  Place  a  rule  on  the  piece  thus 
uncovered  and  count  the  threads  in  both  the  warp  and  the  filling. 
Count  first  the  warp  (lengthwise  the  belt),  then  the  filling,  and 
specify  the  number  of  threads  in  each,  thus :  10-12 ;  11-9,  etc., 
always  stating  first  the  number  of  threads  (picks)  in  the  warp. 

THE  "WEAVE." 

An  "equalized  weave"  is  the  best.  By  this  is  meant  that  the 
warp  and  the  filling  have  both  the  same  number  of  threads  in 
them.  Ravel  out  a  bit  of  the  threads  which  make  up  the  warp  and 
the  filling,  untwist  one  of  them,  then  the  other,  and  see  how  many 
smaller  threads  each  is  composed  of.  The  best  belt,  other  things 
being  equal,  has  the  same  number  of  small  threads  in  both  warp 
and  filling,  or,  as  the  cotton-belt  maker  puts  it,  "the  weave  is 
equalized." 

THE  "STRETCH." 

It  is  well  known  that  these  belts  have  a  tendency  to  stretch 
unduly,  especially  under  over-load.  Under  a  working  tension  of 
about  40  pounds  to  the  inch  of  width,  they  will  not  stretch 
excessively,  provided  they  are  properly  woven.  The  "pick"  has 
considerable  to  do  with  the  stretch  of  a  cotton  belt.  To  test  the 
stretch,  make  two  cuts  into  one  edge  of  the  sample,  say  3  inches 


248  MILLWRIGHTING 

apart.  Be  careful  to  make  the  cuts  the  exact  distance  apart  in  all 
samples  tested,  and  3  inches  is  a  good  distance  for  this  test. 

Having  made  the  cuts,  cut  off  the  rilling  threads  until  a  single 
yarn  from  the  warp  can  be  taken  out.  In  the  belt  that  piece  of 
yarn  was  just  three  inches  long.  Strip  it  between  the  thumb  nail 
and  finger,  rub  off  all  the  paint  and  dried  oil,  and  straighten  the 
fibers  in  that  bit  of  string  or  yarn  until  all  the  kink  caused  by  weav- 
ing has  been  removed.  Do  not  elongate  the  string  by  untwisting  it. 
This  point  must  be  carefully  guarded  against.  It  is  the  object 
to  ascertain  just  how  much  possible  stretch  there  is  in  the  sample 
belt  offered. 

It  is  not  possible  that  all  the  kink  will  be  taken  out  of  the 
threads  when  the  belt  stretches,  but  the  removal  of  the  kinks 
represents  the  limit  of  possible  stretch  in  the  belt,  and  it  forms  a 
good  base  for  comparison,  no  matter  how  much  the  belt  may 
stretch  under  ordinary  or  severe  usage.  We  know  it  must  break 
if  the  possible  stretch — the  straightening  of  the  weave-kinks — 
is  exceeded. 

Having  worked  all  the  kinks  out  of  the  sample  of  warp,  care- 
fully measure  it  again,  and  note  the  increase  in  length.  The 

4—3 

sample  may  come  out  4  inches  long.     This  means  that  = 

3 

33  1/3  per  cent,  possible  stretch.  This  is  too  much.  A  belt  so 
tightly  woven  as  to  contain  33  per  cent,  of  stretch,  will  cut  itself 
to  pieces  much  quicker  than  a  looser  weave.  However,  we  must 
not  go  to  the  other  extreme  and  take  a  flimsy  belt  which  has 
nothing  to  it  but  length.  Select  the  belts  which  give  about  25 
per  cent,  possible  stretch.  Choose  them  in  preference  to  either 
the  high  or  low  percentages  of  stretch. 

WEIGHT  OF  "DucK." 

Ascertain  the  weight  of  the  cotton  duck  from  which  the  belt 
is  made.  This  material  ranges  from  8  to  20  ounces  to  the  square 
yard,  and  insist  that  a  square  yard  be  weighed,  not  a  yard  of  the 
width  of  narrow  duck.  A  further  specification  for  canvas 
(before  it  has  been  filled  with  oil)  is,  that  after  soaked  in  water  for 
10  hours,  and  rubbed  to  take  out  all  the  loading  matter,  it  shall 
not  lose  over  5  per  cent,  of  its  weight. 


BELTS  AND  BELTING  249 

THE  "FILLING." 

Impregnated  stitched  cotton  belts  are  filled  with  various  sub- 
stances and  mixtures  ranging  from  linseed  oil  to  fish  oil  and 
paraffin.  The  choice  of  the  writer  is  for  a  filling  which  will  not 
oxidize,  hence  the  material  resembling  paraffin  with  which  some 
makes  of  these  belts  are  filled  is  desirable.  The  ideal  condition 
in  cotton  belts  is  to  have  them  made  up  "in  the  white"  without 
any  filling  whatever,  and  then  stuff  them  with  cling-surface. 
Such  a  belt  is  perfectly  elastic,  water-proof  and  almost  indestruc- 
tible. It  is  a  rather  costly  belt  to  begin  with  but  it  will  give  many 
years  of  service,  and  if  loaded  only  40  pounds  to  the  inch  of 
width,  it  will  almost  outlast  the  pulleys  it  runs  upon. 

To  sum  up  the  requirements  for  an  "ISC"  belt,  they  are,  briefly 
stated:  "Medium  pick;  equalized  weave;  25  per  cent,  stretch;  10 
to  20-ounce  duck ;  and  non-oxidizable  filling." 

BELT  FASTENINGS. 

The  best  fastening  for  a  belt  is  the  cement  splice.  It  is  far 
beyond  any  form  of  lacing,  belt  hooks,  riveting,  or  any  other 
method  of  joining  together  the  ends  of  a  belt.  The  cement  joint 
is  easily  applied  to  leather  and  to  rubber  belts,  but  to  make  a  good 
cement  splice  in  an  "ISC"  belt  requires  more  time  and  apparatus 
than  the  millwright  has  at  his  disposal  for  that  puropse.  Good 
glue  makes  a  fine  cement  for  leather  belts  and  fish  glue  is  less 
affected  by  moisture.  Many  of  the  liquid  glues  are  fish  glue 
treated  with  acid  so  as  not  to  gelatinize  when  cold.  A  little 
bichromate  of  potash  added  to  ordinary  hot  glue  just  before  it  is 
used  will  render  it  insoluble  in  water  after  exposure  to  sunlight. 

LACING  BELTS. 

Belts  fastened  by  lacing  are  weakened  according  to  the  amount 
of  material  punched  out  in  making  the  holes  to  receive  the  lacing. 
It  is  preferable  to  lace  with  a  small  lacing  put  many  times 
through  small  holes.  Such  a  joint  is  stronger  than  a  few  pieces 
of  wide  lacing  through  a  number  of  large  holes.  Figs.  102  and 
103  illustrate  two  forms  of  belt  lacing,  one  of  which  is  far  pre- 
ferable to  the  other.  The  lacing  shown  by  Fig.  102  is  in  a  double 
leather  belt  5  inches  wide.  The  width  makes  no  difference,  as 
the  strength  will  be  figured  in  percentage  of  the  total  width. 


250 


MILLWRIGHTING 


There  are  four  holes  in  this  piece  of  belt,  each  hole  %  inch  in 
diameter.  The  aggregate  width  thus  cut  out  of  the  belt  is  4X% 
inches=12/8=iyL>  inches.  Then  1.5-^5=0.30,  or  30  per  cent, 
of  the  belt  has  been  cut  away — nearly  one-third  of  the  total 
strength. 

In  Fig.  103,  sketch  A,  a  different  method  is  followed. 
Instead  of  there  being  a  few  large  holes,  there  are  more  smaller 
ones — one-fourth  more,  in  fact.  There  are  five  holes,  each  3/16 
inch  in  diameter,  making  at  total  of  15/16  inches,  or  0.9375-^5= 
18%  per  cent.,  leaving  81  y±  per  cent,  of  the  total  belt  strength 
against  70  per  cent,  in  the  belt  with  large  holes.  A  first-class 
double  leather  belt  will  tear  in  two  under  a  strain  of  about  500 
pounds  to  each  lace  hole,  the  strain  being  applied  in  the  holes  by 
means  of  lacings. 


B. 


FIG.  102— A  WEAK  JOINT 
HOLES  TOO  LARGE. 


A. 


13. 


FIG.  103.— GOOD  JOINT-HOLES 
CORRECTLY  PROPORTIONED. 


Thus  it  would  require  2500  pounds  to  tear  the  5-inch  belt  with 
the  small  lace  holes,  while  the  belt  with  the  large  holes  would  only 
stand  2000  pounds.  Were  the  belt  to  be  figured  boiler  fashion, 
according  to  area  of  material  left  after  the  holes  are  punched, 
then,  taking  the  tensile  strength  of  leather  to  be  3000  pounds  to 
the  square  inch,  the  belt  shown  by  Figs.  102  and  103  being  %  inch 
thick  will  have  a  cross  section  of  5X0.375=1.875  square  inches; 
deducting  30  per  cent,  of  this  for  the  holes,  there  remains  1.125 
square  inches  of  belt  section,  or  enough  to  carry  a  breaking  strain 
of  1.125X3000=3375  pounds.  As  the  lacing  of  this  belt  broke 
it  under  a  strain  of  2000  pounds,  it  is  evident  that  there  is  no 
use  of  paying  for  good  leather  and  then  wasting  it  in  large  lace 
holes. 

The  belt  shown  by  Fig.  103,  sketch  A,  has  81%  per  cent,  of 
1.875  square  inches  of  section,  =1.525  square  inches  left  after 
cutting  out  the  five  holes.  This  amount  of  section  is  good  for 


BELTS  AND  BELTING  251 

3000X1-875=5625  pounds  breaking  strain,  and  as  the  lacing  will 
tear  out  under  2500  pounds,  it  will  be  seen  that  we  cannot  afford 
to  use  lacings  if  the  full  power  of  the  leather  is  to  be  utilized. 
This  under  a  factor  of  safety  of  5  would  be  1125  pounds  to  the 
square  inch,  or  1125X1.525=1715  pounds  working  strain  for 
the  belt,  or  1715-^5=343.5  pounds  to  each  lace.  This,  too,  is  too 
much  as  it  is  less  than  a  factor  of  safety  of  2. 

The  belt  to  carry  40  pounds  working  tension  to  the  inch  of 
width  must  also  carry  about  40  pounds  standing  tension,  making  a 
strain  of  80  pounds  to  the  inch,  or  80X5=400  pounds.  This  is  a 
better  showing  and  gives  a  factor  of  safety  of  2500-^-400=614. 
Still,  we  are  wasting  a  belt  of  5625  pounds  ultimate  strength  in 
order  to  get  from  it  400  pounds  working  strain.  This  means  a 
factor  of  safety  of  over  14  in  the  body  of  the  belt  but  of  only  61,4 
at  the  lacing.  Then  let  us  declare  in  favor  of  the  endless  belt  with 
cement  splice. 

Fig.  103  shows  at  sketch  B  a  method  sometimes  used  to 
relieve  the  lace  holes  of  some  of  the  strain.  Double  rows  of  holes 
are  punched  as  at  a  b,  and  the  lacing  distributed  among  them.  As 
far  as  helping  the  strength  of  the  belt  is  concerned,  this  does 
nothing,  for  all  the  stress  put  upon  the.  belt  by  the  lacing  at  c 
must  be  carried  by  the  belt  section  at  a,  therefore  this  way  of 
punching  holes  does  not  increase  the  section  strength.  Neither 
does  staggering  the  holes  as  shown  at  d  and  e.  The  form  of  hole- 
punching  shown  at  a  b  c,  sketch  B,  is  desirable  for  another  reason. 
It  distributes  the  lacing  very  nicely  and  does  not  make  such  a  lump 
to  thump  when  it  passes  over  the  pulleys. 

BELT  HOOKS. 

There  are  several  styles  of  belt  hooks  in  the  market,  and  all 
of  them  are  of  value  to  the  millwright  in  the  order  of  their  remov- 
ing the  least  amount  of  cross  section  of  belt.  Blake's  belt  stud,  as 
shown  by  Fig.  104,  is  a  fastening  which  does  not  remove  any  of 
the  belt.  The  hole  is  a  slit  made  lengthwise  of  the  belt  as  shown 
by  Fig.  104  at  b.  These  slits  are  all  made  with  a  special  punch- 
cutter,  the  ends  of  the  belt  being  laid  together  and  both  ends  cut 
through  at  the  same  time,  one  hole  through  the  two  ends  being  cut 
at  a  time.  One  of  the  hooks  is  shown  at  d.  It  is  bent  in  the 
manner  shown  to  allow  the  ends  of  the  belt  to  approach  more 


252 


MILLWRIGHTING 


nearly  a  flat  position  as  shown  at  a,  where  two  of  the  hooks  are 
shown  in  place.  A  hook  placed  through  one  of  the  belt  ends  is 
shown  at  c.  When  these  hooks  are  inserted,  they  are  grasped  by  a 
pair  of  pliers  made  to  fit  the  hooks,  and  each 
hook  is  separately  thrust  through  the  ends  of 
the  belting  longitudinally  with  the  slits,  then 
the  hooks  are  turned  crosswise  as  at  a.  After 
the  hooks  are  all  in  place,  the  ends  are  ham- 
mered lightly  while  resting  on  a  pulley  or 
some  hard  surface,  and  the  hooks  are  thus 
well  bedded  in  the  leather.  The  great  trouble 
with  these  hooks  is  that  they  are  very  slow  of  application.  Their 
good  points  are  many:  They  maintain  the  full  strength  of  the 
belt,  no  material  being  cut  away.  They  waste  but  1  inch  of  the 
belt  when  taking  up,  they  may  be  removed  and  used  over  and 
over  again. 

BRISTOL  BELT  HOOKS. 

Fig.  105  illustrates  another  belt  fastening  which  loses  but  very 
little  belt  section,  the  points  of  the  fastenings  being  driven  down 
between  the  fibers  and  cut  but  very  few  of  them.  One  of  the -fas- 
tenings driven  into  place  is  shown  at  a,  while  another  clip  is  in 
place  at  b  all  ready  for  the  hammer,  which  is  the  only  tool 
required  for  applying  these  fastenings.  As  may 
be  seen  at  c,  the  points  which  go  through  the 
belt  are  very  slim  and  quite  small.  They  are 
made  of  rolled  steel  and  will  stand  a  heavy 
strain  without  breaking  or  bending. 

These  fastenings  are  made  in  various  lengths 
and  sizes  to  fit  any  and  all  belt  thickness  and 
width.  After  the  hooks  have  been  driven,  the 
ends  of  the  belt  should,  as  shown  in  the  engra- 
ving, lie  evenly  and  close  together.  If  the  fastenings  are  driven 
properly,  the  belt-ends  will  be  drawn  closely  together,  but  if  the 
steel  points  are  allowed  to  wander  away  from  the  end  of  the  belt 
a  little,  the  job  will  not  be  a  good  one.  The  points  should  project 
through  the  belt  between  1/16  and  1/12  inch  after  having  been 
driven  through  the  belt  into  a  piece  of  soft  wood  placed  under- 
neath. Then  the  belt  should  be  turned  over,  placed  upon  some- 


FIG.    105. 

BRISTOL   BELT 

FASTENINGS. 


BELTS  AND  BELTING  253 

thing  solid — the  rim  of  an  iron  pulley  or  a  bit  of  railroad  iron — 
and  the  points  clinched  and  driven  back  into  the  belt.  They 
should  be  driven  in  so  far  that  they  cannot  touch  the  pulley  at 
all,  and  upon  the  manner  of  the  clinching  and  driving  depends 
largely  the  value  of  this  excellent  fastening — a  very  desirable  one 
when  properly  selected  and  applied. 

THE  JACKSON  STEEL  WIRE  LACING. 

This  belt  fastening,  as  represented  by  Fig.  106,  is  a  most  excel- 
lent one,  and  is  applied  by  a  hand-driven  machine  which  may 
be  kept  in  the  storeroom  and  the  light  belts  brought  to  it,  or 
it  may  be  mounted  on  truck  wheels  and  taken  to  the  belt  when  a 
heavy  one  is  to  be  mended.  As  represented  by  Fig.  106  the 
fastening  is  made  right  in  the  belt,  a  coil  of  steel  wire 
being  fed  from,  by  the  machine  and  wound  into  a  helix  which 
pierces  the  belt  at  every  turn  until  it  extends 
entirely  across  the  end  of  the  belt,  as  visible 
at  a.  After  the  wire  has  thus  been  screwed 
into  the  end  of  the  belt,  it  is  placed  in  the 
machine  and  flattened  down  level  with  the 
surface  of  the  belt,  as  shown  at  c.  It  is 
required  that  the  steel  wires  be  well  pressed 
or  hammered  into  the  leather,  and  if  they  are  FIG.  106.— JACKSON 
entirely  imbedded,  they  will  not  be  cut  or  worn  FASTENING?  BELT 
by  the  pulley. 

After  the  coils  have  been  flatted  as  described,  the  other  end 
of  the  belt  is  brought  around  as  at  c,  the  wires  intermesh  as 
shown,  and  a  wire  or  rawhide  string  d  is  placed  inside  the  wire 
loops  as  shown,  thus  forming  a  hinge  lacing  which  is  perfectly 
flexible  and  which  cuts  but  very  few  fibers.  It  is  safe  to  call 
this  fastening  equal  to  90  per  cent,  of  the  belt  strength.  A  piece 
of  string  may  be  used  in  place  of  the  wire  d,  if  preferred.  This 
lacing  wastes  but  one-half  inch  of  the  belt  when  necessary  to 
put  in  a  new  wire,  and  the  joint  may  be  taken  apart  at.  will  by 
simply  removing  the  wire  or  leather  string  d. 

THE  "CREEP"  OF  BELTS. 

Owing  to  the  elasticity  of  belts — that  quality  which  permits 
a  vertical  belt  to  transmit  power — there  is  a  certain  amount  of 


254 


MILLWRIGHTING 


movement  of  every  belt  in  an  opposite  direction  to  the  motion  of 
the  belt  around  the  pulleys.  This  movement  is  very  small  in 
amount.  It  is  called  the  "creep"  of  the  belt,  and  it  is  usually 
taken  as  2  per  cent,  of  the  actual  velocity  of  the  driving  pulley. 
When  a  belt  approaches  the  driven  pulley  B,  the  belt  is  under 
the  least  tension,  as  it  is  then  the  slack  or  return  fold  and  does 
no  work  except  that  of  holding  itself  against  the  tension  of  its 
own  weight  while  suspended  between  a  and  h.  The  method  of 
ascertaining  the  amount  of  tension  in  this  fold  and  in  the  working 
fold  of  the  belt  will  be  described  in  chapter  XIV. 

When  the  belt  is  running  in  the  direction  of  the  arrows,  Fig. 
107,  and  is  driven  by  pulley  A,  if  marks  were  to  be  made  at  a 
on  the  belt  and  at  b  on  the  rim  of  the  driven  pulley,  exactly  oppo- 


I'lG.   107.— THE  "CREEP"   OF   BELTS. 

site  mark  a,  then  the  pulley  revolved  by  the  belt,  it  would  be 
found  that  when  the  mark  a  left  the  pulley  it  would  no  longer 
coincide  with  mark  b  but  would  be  some  distance  ahead  of  that 
mark,  as  shown  at  c  and  d,  the  former  being  mark  a,  and  d  being 
mark  b.  The  reason  why  these  marks  have  left  each  other  is  that 
when  the  pull  of  the  driver  became  felt  by  the  belt  as  it  passed 
around  pulley  B,  the  belt  was  stretched,  a  certain  amount  by  the 
strain  put  upon  it,  hence  the  belt  was  pulled  ahead  of  the  mark 
on  the  pulley.  The  amount  the  belt  thus  gets  ahead  of  the  pulley 
is  about  1  per  cent,  of  the  distance  traveled  by  the  belt. 

At  the  driving  pulley  A  another  and  similar  lag  takes  place 
between  the  belt  and  the  pulley  face.  Marks  are  shown  at  e 
and  f,  upon  belt  and  pulley  respectively,  and  these  marks  coincide 
at  the  point  shown,  but  as  the  pulley  revolves,  dragging  the  belt 


BELTS  AND  BELTING  255 

with  it  to  the  point  g,  the  tension  upon  the  belt  is  released  and 
the  elasticity  of  the  belt  causes  it  to  shorten  to  its  normal  condi- 
tion again,  falling  back  from  g  to  h.  In  this  case  the  belt  has 
fallen  behind  the  pulley.  On  the  driven  pulley  B  the  pulley  has 
fallen  behind  the  belt.  In  both  cases  the  loss  is  about  the  same, 
and  both  go  to  make  pulley  B  revolve  slower  than  pulley  A  to  the 
extent  of  another  1  per  cent.,  making  a  loss  of  2  per  cent,  in  all. 

In  laying  down  belt  power  transmissions,  where  considerable 
exactness  of  speed  is  required,  it  is  necessary  to  allow  about  2  per 
cent,  for  the  creep  of  the  belt,  and  if  the  driven  shaft  B  were 
required  to  run  at  exactly  100  r.p.m.  it  would  be  necessary  to  give 
the  driving  shaft  A  a  speed  of  102  r.p.m.  in  order  to  make  up  for 
the  creep  of  the  belt  in  the  manner  described.  Thus,  for  a  shaft 
belted  7  removes  from  the  prime  mover,  the  speed  of  that  mover 
would  have  to  be  increased  nearly  15  per  cent.  (14.86)  to  make  up 
for  the  creep  of  belts. 

The  above  allowance  is  a  very  important  one  when  exact 
speeds  are  required,  and  it  explains  why,  in  some  cases,  the  actual 
speed  does  not  come  up  to  the  requirements,  even  though  the 
pulleys  all  figure  correctly  to  give  the  required  speed. 

PUTTING  BELTS  ON  PULLEYS. 

Some  workmen  have  developed  the  very  bad  habit  of  spli- 
cing belts  together  off  the  pulleys  and  then  running  them  on. 
While  this  answers  very  well  for  small,  light  belts,  it  should  never 
be  practised  with  a  belt  more  than  8  inches  wide.  The  writer  has 
seen  belts — even  engine  belts — over  14  inches  wide,  roped  to  the 
sides  of  their  pulleys  and  run  on  by  power,  to  the  detriment  and 
lasting  injury  of  the  belts  thus  mismanaged.  A  wide  belt  being 
forced  over  the  sharp  edge  of  a  pulley  is  subject  to  very  severe 
strains,  and  in  some  cases  the  fibers  are  strained  beyond  their 
elastic  limit  by  so  doing. 

Whenever  a  belt  of  more  than  8  inches  in  width  must  be 
placed  on  its  pulleys,  then  use  a  belt  clamp  and  do  the  work  in  a 
mechanical  manner.  There  are  various  kinds  of  clamps  to  be 
obtained,  some  very  crude,  others  well  made  and  with  the  nuts 
geared  together  so  that  turning  a  single  crank  or  rachet  operates 
both  sides  of  the  clamp.  In  case  of  very  heavy  belts,  it  may  be 
the  thing  to  pull  the  belt  almost  into  position  by  means  of  a  rope 


256  MILLWRIGHTING 

tackle.  To  hitch  this  to  a  belt,  simply  lay  a  plank  or  short  piece 
of  timber  on  either  side  of  the  belt,  take  a  timber  hitch  around  the 
wood,  as  shown  by  Fig.  108,  and  go  ahead  with  the  hauling. 

A  hitch  of  this  kind  will  hold  the  belt  securely  and  there  is 
no  danger  of  cutting  or  otherwise  injuring  the  belt  as  if  the  rope 
were  attached  directly  to  it.  When  using  the  belt  clamps,  particu- 
larly those  of  inferior  design,  trouble  may  be  met  with  through 
the  slipping  of  the  belt,  the  clamps  not  holding  it  securely.  The 
usual  remedy  in  such  cases  is  to  hold  a  plank  under  the  belt  close 
against  the  clamp  which  slips,  place  a  bit  of  board  in  similar  posi- 
tion of  top,  and  drive  nails  enough  through  the  board  and  belt  to 
hold  the  latter  securely. 

It  usually  requires  but  very  little  in  addition  to  the  clamps, 
defective  though  they  may  be,  to  hold  the  belt,  and  the  best  way 


FIG.    108.— ROPE-HITCH    FOR    BELTS. 

in  case  the  clamp  does  slip  is  to  apply  a  couple  of  double-screw 
hand-  clamps  close  against  the  jaws  of  the  belt  clamp.  This  will 
do  the  business  as  well  as  the  nails,  and  it  does  not  tear  or  other- 
wise disfigure  the  belt. 

Frequently,  trouble  of  this  kind  is  caused  solely  by  attempting 
to  tighten  the  belt  too  much.  More  strain  than  the  workman 
has  any  idea  of  it  put  upon  the  belt,  and  the  pressure  upon  the 
shaft  bearings  is  as  great  as  the  tension  in  the  belt.  The  strain 
caused  in  any  belt  by  drawing  the  ends  together  until  it  hangs 
in  a  very  flat  curve  is  measured  entirely  by  the  weight  of  the  belt, 
the  distance  between  the  pulleys,  and  the  sag  of  the  belt  between 
the  points  of  support.  The  next  chapter  will  describe  a  method 
by  which  the  strain  in  a  belt  may  be  ascertained  by  the  sag 
between  the  pulleys,  and  the  power  actually  transmitted  by  the  belt 
may  be  calculated  with  considerable  accuracy  by  the  sag,  weight 
and  distance  above  mentioned. 


CHAPTER  XIV. 

SETTING  UP  MACHINES. 

The  actual  work  of  getting  machines  off  of  a  car  or  boat 
into  the  shop  and  into  their  proper  positions  belongs  to  the  rig- 
ger more  than  to  the  millwright,  but  the  millwright  is  supposed 
to  be  as  good  a  rigger  as  he  is  carpenter  and  blacksmith  and  to 
be  able  to  handle  all  sorts  of  tackle  like  a  stevedore,  tie  knots  like 
a  sailor,  and  judge  weights  and  distances  by  the  unaided  eye  like 
the  combination  of  a  standard  weighing-scale  and  a  range-finder. 
All  this  is  in  a  day's  work  and  the  millwright  does  it  as  a  matter 
of  course,  doing  it  better  or  worse  according  to  his  experience 
and  skill. 

SKIDS  AND  ROLLERS — THE  "WHISKY"  JACK. 

The  most  common  method  of  unloading  machinery  is  the 
time-honored  skid  and  roller,  each  machine  being  pried  up  by 
bar,  lever  and  "bait"  until  skids  and  rolls  can  be  placed  under- 
neath and  the  machine  can  be  moved  along  to  its  proper  position. 
The  screw-jack  is  the  mainstay  of  the  millwright  for  this  kind  of 
work,  though  a  "whisky"- jack  is  a  great  time  and  labor  saver* 
The  "whisky"  or  hydraulic  jack  is  merely  a  small  hydrostatic 
press  made  in  portable  form,  the  pump  being  contained  inside 
the  plunger,  the  cylinder  forming  the  body  of  the  jack.  The 
"whisky"-jack  is  so-called  because  it  uses  alcohol  as  a  liquid  for 
operating  the  hydrostatic  part  of  the  jack.  Water  may  be  used  in 
summer,  but  it  is  apt  tcf  rust  some  of  the  parts,  and  in  cold  weather 
it  freezes.  When  the  "whisky"- jacks  first  were  put  into  use 
with  their  reservoirs  filled  with  nice  grain  alcohol,  some  of  the 
workmen  promptly  rose  to  the  opportunity,  drank  the  alcohol  and 
filled  the  jacks  with  more  water. 

THE  OPERATION  OF  "WHISKY"  JACKS. 

To  operate  one  of  these  jacks,  insert  the  lever  so  that  the 
shoulder  on  one  side  of  the  lever  will  project  downward  and 

257 


258  MILLWRIGHTING 

strike  a  lug  on  the  head  of  the  jack.  An  ordinary  pumping  move- 
ment of  the  lever  will  then  force  the  liquid  out  of  the  piston  into 
the  reservoir  underneath  it,  causing  the  jack  piston  and  head  to 
rise  according  to  the  bulk  of  liquid  displaced.  To  lower,  reverse 
the  lever,  turning  the  lug  uppermost,  then  bear  down  on  the  lever 
and  the  valve  in  the  pump  will  be  forced  to  open,  allowing  the 
liquid  to  pass  back  into  the  piston  reservoir.  In  some  jacks  this 
form  of  construction  is  reversed,  the  piston  standing  upon  the 
foot  or  base  and  the  cylinder  being  attached  to  the  head  of  the 
jack.  Sometimes  the  arrangement  of  the  pump  lever  is  opposite 
that  described  above,  the  lug  being  placed  uppermost,  and  a  lift- 
ing motion  being  necessary  to  lower  the  jack  after  the  lever  has 
been  reversed. 

THE  BALL-BEARING  SCREW-}ACK. 

There  is  also  a  most  excellent  form  of  jack  known  as  the  "ball- 
bearing screw-jack,"  in  which  there  is  a  set  of  balls  between  the  end 
of  the  lifting  screw  and  the  head  of  the  jack.  As  friction  usually 
consumes  more  than  one-half  the  power  applied  to  the  plain  screw- 
jack,  the  value  of  the  ball  arrangement  is  obvious.  In  this 
jack  there  is  a  pair  of  miter  gears  with  a  ratchet  arrangement  on 
the  power  lever,  thus  making  it  possible  to  "pump"  this  excel- 
lent form  of  jack  the  same  as  the  whisky- jack,  and  the  ratchet 
attachment  permits  the  jack  to  be  worked  in  restricted  quarters 
equally  as  well  as  the  other. 

In  operating  any  and  every  form  of  jack,  the  one  point  to  be 
closely  watched  is  the  distance  which  the  jack  has  been  extended. 
In  the  whisky- jack,  too  great  an  extension  will  permit  the  cyl- 
inder to  be  scored  by  the  piston  or  plunger,  and  the  jack  becomes 
useless  until  machine-shop  repairs  can  be  made.  In  any  form 
of  screw-jack,  the  same  danger  exists,  but  if  the  jack  be  extended 
too  far,  the  thread  may  be  stripped  off  the  screw  or  out  of  the 
nut,  and  the  unfortunate  workman  is  sure  of  a  "wigging"  from 
the  foreman  for  "slumping  that  jack." 

CAUTION  WHEN  JACKING-UP  MACHINERY. 

The  millwright  should  make  it  an  invariable,  infallible  rule 
to  always  follow  up  very  closely  with  substantial  blocking  any 
weight  or  machine  which  is  being  jacked  up.  Never  trust  a 


SETTING  UP  MACHINES  259 

machine  to  jacks.  Follow  up  with  blocking  as  fast  as  the  machine 
is  raised,  and  build  the  blocking  fair  and  square  and  heavy  enough 
to  carry  the  machine  at  all  times  should  its  weight  be  suddenly 
and  unexpectedly  dropped  upon  the  follow-up  blocking.  Many 
a  man  has  been  mained  for  life  or  killed  outright  by  neglect  of 
the  simple  precaution  of  building  adequate  follow-up  blocking. 
And  "building  adequate  blocking"  does  not  mean  merely  filling 
the  space  below  the  machine  with  blocks  piled  one  on  top  of 
another.  It  means  the  construction  of  a  substantial  cribwork 
which  will  not  cripple  sidewise  or  "buckle"  out,  and  which  is 
plenty  strong  enough  to  carry  the  machine  when  the  jacks  must 
be  set  to  a  higher  level.  "Never  allow  two  parallel  blocks  under 
a  machine"  is  the  only  way  in  which  to  secure  safe  and  substantial 
blocking  when  jacking  a  machine  up  or  down. 

USING  SKIDS  AND  ROLLERS. 

Once  a  machine  has  been  safely  placed  on  skids  and  rollers, 
never  move  it  an  inch  before  adequate  means  have  been  devised 
for  preventing  a  "run"  or  a  "back  run."  When  a  machine  goes 
ahead  too  far  and  gets  off  the  rollers,  there  is  a  nasty  job  to  be 
done  in  replacing  the  rolls,  even  if  no  damage  be  done  to  machine 
or  to  runway.  No  heavy  machine  should  be  started  upon  the 
rolls  without  first  attaching  a  pull  tackle  and  a  back  haul.  The 
former  may  be  either  a  heavy  rope  tackle,  a  set  of  differential 
chain  tackle,  or  a  cable  and  winding  drum,  as  may  be  at  hand. 
The  back  haul  preferably  should  be  a  rope  and  block  tackle  heavy 
enough  to  stop  the  machine,  though  failing  to  possess  block  tackle 
for  this  purpose,  a  plain  hitch  may  be  made  of  a  heavy  rope  which 
is  "snubbed"  around  some  convenient  object,  a  post  of  a  building, 
a  "dead  man"  or  even  around  one  of  the  rails  of  the  car-track. 

THE  "HOLLER-BOSS." 

Above  all  things,  when  jacking,  skidding  or  otherwise  moving 
heavy  machinery  or  raising  the  timbers  of  a  building,  see  to  it 
that  only  one  man  gives  orders.  Let  one  man  do  the  "hollering" 
and  give  all  the  orders.  The  millwright  may  be  the  one  to  do 
this,  but  the  writer  has  found  that  in  every  gang  of  workmen 
there  is  some  one  man  who  though  he  may  not  be  worth  shucks 
for  doing  actual  work  himself,  still  he  can  get  a  lot  of  work  out 


260  MILLWRIGHTING 

of  the  others,  and  usually  this  sort  of  a  man  really  does  well  in 
watching  tackle,  skids  and  rolls,  and  in  making  hitches  and  knots. 
When  such  a  man  is  appointed  "holler  boss"  the  millwright 
is  at  liberty  to  give  his  attention  to  the  safety  of  the  entire  opera- 
tion. The  millwright  should  always  respect  the  authority  given 
to  the  "holler  boss"  and  refrain  from  giving  any  orders  direct 
to  the  men  by  giving  all  directions  through  the  boss.  Even  on 
quite  small  jobs  this  method  works  to  perfection,  and  it  only 
requires  a  very  short  time  to  establish  things  upon  a  system  which 
will  permit  the  millwright  to  tell  the  boss  to  put  such  a  machine 
or  a  certain  timber  in  a  certain  position.  The  ''holler  boss"  will 
do  the  rest,  and  not  a  single  conflicting  order  will  be  heard  dur- 
ing the  entire  operation.  The  millwright  thus  doubles  his  work- 
ing capacity,  he  can  have  the  machinery  hoisting  going  on  in 
good  shape  and  at  the  same  time  have  other  gangs  putting  ahead 
other  work.  Meanwhile,  he  will  keep  an  eye  out  in  every  direc- 
tion for  the  "unexpected  which  always  happens." 

USING  DIFFERENTIAL  CHAIN  HOISTS. 

Any  job  containing  an  engine  of  at  least  75  horse-power 
should  be  permanently  supplied  with  two  sets  of  differential  chain 
tackle,  one  set  having  a  capacity  of  at  least  one  ton,  the  larger 
set  having  a  capacity  of  three  tons.  In  using  tackle  of  this  char- 
acter the  greatest  caution  should  be  observed  to  see  that  the  tackle 
is  not  overloaded.  When  a  chain  is  loaded  too  heavily,  and  the 
steel  is  strained  past  its  elastic  limit,  the  chain  links  stretch  and 
fail  to  run  smoothly  in  the  wheels  of  the  blocks. 

The  trouble  is  hardly  noticeable  at  first,  merely  a  little  stick- 
ing of  the  chain  at  one  or  more  points,  but  soon  the  chain  refuses 
to  run  at  all  under  a  heavy  load,  the  links  climbing  endwise  over 
the  pockets  in  the  sheave  or  pulley  and  bringing  up  with  a  slam 
and  a  bang  against  the  guide  casting  which  prevents  the  chain 
from  jumping  out  of  the  groove  in  the  sheave.  When  this  hap- 
pens, it  is  necessary  to  slack  back  a  little  on  the  tackle,  the  chain 
adjusts  itself  in  the  pockets  again,  and  a  few  more  pulls  can  be 
made  on  the  hand  chain  until  another  accumulation  of  length  of 
the  links  forces  another  back  pull.  The  only  remedy  for  this  is 
to  obtain  a  new  chain,  the  old  one  having  become  stretched 
through  overloading.  For  this  reason,  avoid  overloading  chain 


SETTING  UP  MACHINES  261 

hoisting  tackle,  and  avoid  any  sudden  yanking  of  the  chain  while 
the  tackle  is  under  load.  Chain  tackle  is  very  tender  in  this  direc- 
tion, and  it  is  easy  to  spoil  a  chain  by  very  slight  misuse. 

CAUTION  WHEN  HOISTING  MACHINERY. 

The  workman  is  naturally  careless  and  very  apt  to  take  need- 
less risks.  The  one  great  caution  necessary  when  hoisting 
machinery  or  other  material  is,  "Never  go  or  work  unnecessarily 
under  the  suspended  object."  Men  are  careless,  and  all  ropes 
and  chains  are  bound  to  break  some  times ;  therefore*  the  mill- 
wright who  would  avoid  damage  suits  for  his  employers  will  see 
to  it  that  no  work  is  unnecessarily  done  under  objects  which  are 
hanging  from  ropes,  chains  or  cables.  Remember  that  the  rope 
or  chain  is  bound  to  break  "some  time"  and  consider  always  that 
"some  time"  is  right  at  hand  and  that  the  only  safe  way  is  to 
"stand  from  under."  Keep  from  under  yourself,  and  keep  your 
men  out  too. 

THE  WIRE  CABLE  AND  SNATCH-BLOCK  METHOD. 

The  writer,  having  used  differential  chain  hoists  and  rope 
tackle  for  many  years  in  the  erection  of  machinery  and  buildings, 
has  found  that  there  is  a  much  better  method  of  sending  aloft 
timber,  machines  and  parts  of  machines.  The  method  referred 
to  is  by  the  use  of  a  winch,  or  winding  drum,  some  %-inch 
flexible  steel-wire  cable  and  a  number  of  single,  double  and  four- 
fold blocks,  including  a  few  snatch-blocks.  The  winch  or  wind- 
ing drum  is  to  be  permanently  located  upon  the  factory  site  in 
such  a  position  that  as  soon  as  power  is  to  be  had  the  winding 
drum  may  be  connected  to  line  shaft  or  engine. 

Meanwhile,  permanently  erect  the  winding  drum,  and  lead  the 
cable  through  the  necessary  snatch-blocks  to  any  part  of  the  mill 
where  hoisting  work  is  to  be  done.  The  text-books  tell  us'that  a 
steel  cable  should  never  be  used  on  a  sheave  less  than  30  diam- 
eters of  the  cable.  That  is  good  engineering  where  the  cable  is 
to  be  used  for  a  long  time,  but  a  19-strand  wire  cable  will  work 
well  for  hoisting  over  and  around  6-inch  sheaves  such  as  are 
usually  put  into  blocks  for  %-inch  rope.  When  a  light  hoist  is 
to  be  made,  pass  the  cable  through  a  single  block  and  attach  direct 
to  the  weight  to  be  lifted.  When  more  of  a  hoist  is  to  be  made, 


262 


MILLWRIGHTING 


use  a  double  and  a  single  block  and  reeve  the  cable  as  for  an 
ordinary  rope  tackle.  When  still  heavier  work  is  to  be  done,  use 
the  four-fold  and  three-fold  blocks  and  double  up  on  the  cable 
accordingly,  which  should  be  from  250  to  300  feet  long  for  a 
100-horse-power  plant  and  longer  when  the  factory  covers  con- 
siderable ground. 

STRENGTH  OF  WIRE  CABLE. 

Wire  rope  is  made  in  a  variety  of  ways,  and  the  "standing" 
rope  should  not  be  mistaken  for  "transmission"  rope,  neither 
should  the  latter  be  confused  with  "hoisting"  rope.  The  fol- 
lowing table  gives  the  weight  to  100  feet,  breaking  strain  and 
safe  working  load  of  various  kinds  of  iron  and  steel-wire  cables, 
%  inch  in  diameter,  with  19  strands  and  hemp  core : 

IRON  AND  STEEL  WIRE  CABLE. 


19  -strand,  I 

"  Cable,  Hemp  Core. 

Weight  to 
100  feet. 

Breaking 
Strain. 

Safe 
Load. 

Hoisting,  Iron 

35  Ibs 

6  960 

1  000 

Hoisting,  Cast 

Steel 

39    " 

14  000 

3  000 

Transmission, 
Transmission, 
Transmission, 

"  7-wire"  Iron  
"  7-wire"  Cast  Steel. 
"19-wire"  Plow-Steel 

31    " 
31    " 
39   " 

5,660 
12,000 
20,000 

1,500 
3,000 
4,000 

It  may  be  seen  that  %-inch  cable  is  made  all  strengths,  but 
the  "hoisting"  is  the  only  one  which  should  be  used  for  the  severe 
work  of  passing  around  the  small  sheaves  used  for  the  purpose 
as  described.  The  writer  has  used  both  iron  and  steel  hoisting 
cable  for  this  purpose  and  finds  that  the  iron  lasts  the  longest, 
but  if  the  steel  be  worked  under  the  light  load  tabulated  for  the 
iron,  then  the  steel  will  outlast  the  iron  cable. 

With  the  ordinary  two-crank  winding  drum  as  used  on  der- 
ricks, 1000  pounds  is  about  all  two  men  care  to  handle  in  the  form 
of  direct  pull  on  the  cable.  With  the  winding  drum  geared  6  to 
1,  cranks  18  inches  long  and  the  winding  drum  6  inches  in  diam- 
eter, arranged  as  shown  by  Fig.  109,  the  power  exerted  upon  the 
cable  by  two  men  on  the  cranks  would  be  about  16  pounds  apiece, 
or  32  pounds  in  all.  A  man  can  exert  more  force  for  a  short 
time  on  a  crank,  but  this  is  all  that  the  average  man  can  con- 
tinue to  exert  for  any  considerable  length  of  time,  and  even 
with  16  pounds  a  man  will  want  to  stop  and  rest  frequently. 


SETTING  UP  MACHINES 


263 


The  leverages  of  the  crank,  gears,  winding  drum,  etc.,  are 
as  shown  at  a,  Fig.  109,  and  expressed  arithmetically  the  lever- 
age exerted  as  pull  on  the  cable  is  as  follows  : 

32X18X15 

-  =1152- 


The  pull  on  the  cable  will  then,  allowing  nothing  for  friction, 
be  about  the  1000  pounds  safe  load  with  which  it  is  credited  in  the 
table.  Friction  will  cut  down  the  strain  exerted  on  the  cable,  and 
extra  hard  pulling  will  sometimes  balance  the  friction  loss,  so  that 


FIG.   109.— WIRE-CABLE  AND  SNATCH-BLOCK  HOIST. 

the  cable  will  have  about  its  1000  pounds  safe  load  as  an  average. 

The  manner  in  which  the  drum  is  erected  against  a  couple  of 
posts  is  shown  at  b,  and  the  snatch-block  located  at  c  permits  the 
cable  to  be  lead  in  any  direction,  east,  west,  north  or  south,  that 
may  be  required  by  the  work  in  hand,  the  only  requirement  being 
that  snatch-block  c  be  located  opposite  the  middle  of  the  winding 
drum  in  order  that  the  cable  may  lead  square  toward  the  drum  at 
all  times. 

At  d  a  temporary  timbering  is  placed  for  attaching  the  four- 
sheave  block  e,  and  the  three-sheave  block  /  enables  the  1000 


264 


MILLWRIGHTING 


pounds  pull  on  the  cable  to  sustain  a  load  of  7000  pounds  at  /,  or 
1000  pounds  for  each  fold  of  cable  between  blocks  e  and  /. 
Should  it  be  desired  to  work  this  tackle  to  the  limit,  a  four-sheave 
block  may  be  placed  at  /,  and  in  that  case,  the  dead  end  of  the 
cable  must  be  attached  to  the  upper  block,  as  shown  by  Fig.  109. 
In  case  a  three-sheave  block  is  used  at  /,  then  the  cable  must  have 
its  dead  end  attached  to  that  block.  In  any  rope  or  cable  tackle, 
the  ratio  of  the  two  forces — the  power  applied  and  the  weight 
lifted — may  be  taken  as  the  number  of  folds  or  rope  shortened 
between  the  blocks  e  and  /.  Hence,  with  2  four-sheave  blocks  there 
will  be  8  folds  of  rope  shortened,  and  the  weight  balanced  at  / 
by  1000  pounds  pull  on  the  cable  will  be  8X1000=8000  pounds,  or 
4  tons.  Thus  the  wire  cable  and  snatch-block  arrangement  com- 
bines all  the  lifting  advantages  of  1000-pound  and  4-ton  tackles. 

STRENGTH  OF  IRON-STRAPPED  BLOCKS. 

It  is  important  when  arranging  a  hoist  as  above  described  that 
blocks  be  procured  which  will  stand  a  load  of  more  than  1000 
pounds  to  each  fold  of  cable.  To  this  end,  steel  blocks  should  be 
obtained,  unless  very  large  blocks  with  sheaves  made  of  metal  and 
mounted  on  friction  rollers  can  be  obtained.  For  wooden — ordi- 
nary "mortise" — blocks,  the  usual  strength  is  given  by  the  B.  &  L. 
Block  Co.  for  their  iron-strapped  blocks  as  follows : 

WORKING    STRENGTH  OF   BLOCKS. 


Dia. 

of 
Sheave 

ins. 

Regular 
Mortise 
Blocks 
Pounds. 

Extra  Wide 
and  Heavy 
Mortise 
Pounds. 

5 

250 

6 

350 

7 

600 

8 

1,200 

2,000 

9 

2,000 

10 

4,000 

6,000 

12 

10,000 

12,000 

14 

16,000 

24,000 

16 

36,000 

18 

50,000 

20 

90,000 

In  using  this  table  it  is  evident  that  it  may  be  interpreted  in 
much  the  same  manner  as  the  table  of  sheave  diameters  for  wire 
rope.  There  the  table  is  made  up  on  a  ratio  something  like  30 
diameters  of  the  cable  for  each  sheave,  and  for  our  factory  hoist- 


SETTING  UP  MACHINES  265 

ing  use  we  disregard  the  rule  altogether,  and  instead  of  using  a 
15-inch  sheave  for  a  %-inch  cable,  we  put  the  cable  through  an 
ordinary  6-inch  block  which  the  table  says  is  good  for  only  350 
pounds,  whereas  we  apply  1000  pounds  load.  In  both  cases  we 
prefer  to  let  the  cable  and  blocks  withstand  the  severe  usage  as 
best  they  may,  because  they  are  only  subjected  to  it  for  short 
periods  and  at  very  infrequent  times.  Were  the  cable  and  blocks 
to  be  in  constant  use,  then  they  should  be  calculated  according  to 
the  tables,  but  for  the  very  short  time  they  are  to  be  in  use  we  will 
sacrifice  them  to  saving  in  first  cost  and  let  them  wear  out.  But  it 
is  well  in  selecting  blocks  to  get  them  with  as  large  sheaves  as 
possible,  for  the  reasons  stated. 

PLACING  MACHINES  UPON  FOUNDATIONS. 

Great  care  is  necessary  when  placing  machines  upon  ready- 
built  foundations  to  prevent  the  cracking  or  crumbling  of  portions 
of  the  concrete  or  masonry.  It  requires  considerable  time  for 
cement  to  become  solid,  and  unless  the  foundation  has  been  built 
for  at  least  28  days  and  has  been  kept  constantly  wetted  during 
that  period,  it  is  unsafe  to  pry  with  a  bar  upon  any  portion  of  the 
foundation  without  first  placing  a  thick  plank,  timber,  or  piece  of 
iron  at  the  point  where  pressure  is  to  be  applied.  Therefore,  it  is 
necessary  when  placing  heavy  machinery  upon  green  foundations 
to  proceed  with  the  greatest  care  to  prevent  damage  or  destruction 
to  the  not  fully  hardened  masonry  or  concrete. 

In  cases  of  this  kind,  build  heavy  timber  or  plank  runways,  roll 
the  machine  to  the  exact  position  it  is  to  occupy,  then  jack  it  down 
to  the  foundation,  taking  care  to  "cut  and  trim"  the  machine 
exactly  by  moving  it  by  the  jacks  until  it  will  settle  into  place  with- 
out needing  a  single  pry  either  sidewise  or  lengthwise. 

It  sometimes  happens  that  after  a  machine  has  been  placed 
upon  its  foundation  it  is  found  necessary  to  raise  a  portion  of  the 
machine  or  to  elevate  one  side  or  one  end  a  fraction  of  an  inch 
in  order  to  secure  the  required  level.  Sometimes  this  proves  a 
very  awkward  bit  of  work  as  there  is  no  chance  of  getting  a  jack 
underneath  any  portion  of  the  machine,  and  in  cases  like  this  the 
wire  cable  hoist  comes  in  very  handy.  It  requires  but  a  very  short 
time  to  rig  the  four-sheave  tackle  over  any  point  in  the  factory, 
and  if  the  machine  weighs  not  more  than  8  tons,  one-half  of  it 


266 


MILLWRIGHTING 


may  be  easily  raised  by  the  winch  and  the  heavy  four-sheave 
tackle,  thus  avoiding  the  necessity  of  putting  any  strain  whatever 
upon  the  foundation  through  the  means  of  levers  or  jacks. 

LEVER  AND  CABLE-HOIST  LIFT. 

When  the  heavy  end  of  a  machine  must  be  raised  as  above 
described,  and  it  is  feared  that  the  weight  is  beyond  the  capacity 
of  any  hoist  available,  then  resource  may  be  had  to  the  combined 
lever  and  cable  hoist  shown  by  Fig.  110.  This  device  may  be 


-k 


FIG.     110.— LEVER    AND    CABLE-HOIST    LIFT. 

used  equally  well  with  a  jack  or  the  differential  chain  hoist  as 
with  the  ware-cable  business.  As  shown,  it  consists  of  a  heavy 
timber,  one  end  of  which  is  attached  by  a  sling  g  to  the  lower 
block  of  the  cable  tackle.  The  other  end  of  the  timber  rests  upon 
a  block  placed  across  the  top  of  the  machine,  as  at  h.  At  the 
other  end  of  the  machine — the  end  to  be  raised — the  timber  is 
made  fast  by  means  of  a  chain  or  a  yoke  to  some  convenient 
shaft  or  projecting  portion  of  the  frame,  as  at  k.  A  pull  at  f  will 
result  in  raising  a  load  at  k  heavier  than  4000  pounds  in  the  ratio 
of  the  horizontal  distances  g  k  and  k  j.  Thus,  if  k  g  be  twice 
k  j,  then  our  limit  force  of  4000  pounds  at  f  will  handle  8000 


SETTING  UP  MACHINES  267 

pounds  at  k,  thereby  enabling  a  pretty  heavy  load  to  be  lifted 
by  32  pounds  exerted  on  the  cranks  of  the  wire-cable  hoisting 
device. 

FITTING  A  MACHINE  TO  ITS  FOUNDATION. 

The  old-time  method  of  fitting  and  leveling  a  machine  to  its 
foundation  by  means  of  the  bush-hammer  is  pretty  well  out  of 
date  nowadays.  That  method  went  out  of  use  with  the  hammered 
stone  caps  for  machinery  foundations.  Nowadays  it  is  good 
enough  io  level  up  the  machine  on  steel  wedges  (scraps  of  flat 
iron  from  the  boiler  shop)  and  then  fill  between  machine  and 
foundation  with  brimstone  or  cement.  The  latter  is  as  good  as 
the  brimstone,  but  it  does  not  set  as  quickly.  Common  calcined 
plaster  (plaster  of  paris  or  sulphate  of  lime)  answers  very  well 
for  leveling  up  with,  though  this  substance  will  not  withstand  the 
action  of  acids  a§  well  as  brimstone  or  cement. 

THE  PLASTER  METHOD. 

There  is  no  fear  of  plaster  proving  too  weak  to  carry  any 
load  likely  to  be  placed  upon  it,  for  plaster  mixed  with  one-half 
its  weight  of  water  will  stand  a  pressure  of  500  pounds  to  the 
square  inch  after  setting  one  hour.  At  24  hours  it  will  withstand 
over  1000  pounds  to  the  square  inch,  and  after  standing  several 
weeks  its  crushing  strength  increases  to  over  2300  pounds  to  the 
square  inch.  This  is  as  strong  as  most  concrete,  therefore  the 
millwright  need  have  no  fear  about  using  that  material.  The  sev- 
eral determinations  above  mentioned  were  made  by  the  author 
in  person  upon  cubes  1  inch  on  a  side. 

Plaster  to  be  poured  should  be  mixed  with  more  than  one-half 
its  weight  of  water.  That  amount  gives  a  paste  which  can  be 
shaken  from  a  trowel  but  which  will  not  drop  without  shaking. 
Ascertain  by  trial  how  much  more  water  is  needed  to  make  up 
plaster  which  will  flow  freely,  then  weigh  out  charges  of  plaster 
and  of  water  and  have  them  at  hand  ready  for  use.  After  the  clay 
or  putty  dams  have  been  placed  around  the  machine  footing,  mix 
together  the  water  and  the  plaster,  each  charge  ranging  from  one 
pound  to  ten  pounds  according  to  the  size  of  the  job.  It  is  better 
not  to  mix  more  than  ten  pounds  of  plaster  at  a  time.  Mix  the 
water  and  plaster  as  quickly  as  possible,  and  pour  at  once.  Never 


268  MILLWRIGHTING 

wait  an  instant  after  they  are  mixed ;  pour  quickly  and  paddle  the 
mixture  along  into  place  if  necessary.  Above  all  things,  do  it 
quickly. 

SETTING  MACHINES  WITH  CEMENT,  PLASTER  AND  BRIMSTONE. 

Before  the  cement,  brimstone  or  plaster  filling  can  be  turned 
loose,  the  machine  must  have  been  accurately  leveled  and  alined 
with  the  main  shaft — or  with  the  permanent  targets  of  the  factory 
as  described  on  page  231,  chapter  XII,  and  in  chapter  III,  also  in 
chapter  XI,  page  204. 

When  melting  brimstone,  use  a  vessel  with  a  tight  fitting 
cover.  The  brimstone  is  very  apt  to  catch  fire  during  the  melting 
operation,  in  fact  it  will  probably  be  on  fire  a  dozen  times  before 
it  is  fully  melted.  Just  put  the  tight  fitting  cover  in  place  and  the 
fire  will  go  out.  Brimstone  burns  very  slowly,  with  a  quiet  and 
very  small  blue  flame  which  is  extinguished  easily  when  air  is 
prevented  from  reaching  the  brimstone.  Use  a  very  light  fire 
and  heat  the  stuff  very  slowly  and  do  not  heat  too  hot  after  it  is 
melted.  Brimstone  heated  to  600  degrees  becomes  waxy  and  does 
not  flow  readily.  Therefore  heat  only  hot  enough  to  become 
fairly  melted. 

When  running  cement  or  calcined  plaster  under  a  machine, 
poke  with  a  wire  into  the  remote  places — the  little  pockets,  so 
to  speak — to  make  sure  that  the  corners  and  holes  are  all  filled 
with  the  cement  or  plaster.  Sometimes  the  pockets  become  "air- 
bound"  and  the  material  will  not  flow  into  them  until  a  little  pok- 
ing starts  the  stuff  to  flowing.  Brimstone  seems  to  flow  into  .the 
corners  better  and  easier  than  cement,  but  it  is  well,  even  with 
that  substance,  to  see  to  it  that  the  inner  portions  and  the  corners 
farthest  from  the  pouring  point  are  well  filled. 

ALINING  SHAFTING  WITH  A  PLUMB-BOB. 

Several  methods  of  alining  have  been  discussed  in  the  preced- 
ing chapters  and  each  method  has  its  value  for  particular  cases 
and  conditions.  There  is  another  method  which  the  author  uses  a 
good  deal  when  setting  rough  machinery  and  when  the  transit  is 
conspicuous  by  its  absence.  This  method,  for  the  want  of  a 
better  name,  may  be  called  the  "single  plumb-bob"  method  and 


SETTING  UP  MACHINES 


269 


the  manner  of  working  it  may  be  better  understood  by  reference 
to  Fig.  111. 

A  line  is  stretched  from  batters  or  targets  a  and  b,  and  a 
plumb-bob  is  suspended  from  the  line  at  some  convenient  point — 
it  matters  little  where,  or  at  which  end  of  the  line,  which  may  be 
several  inches  or  a  number  of  feet  from  the  line  which  is  to  be 
brought  parallel  with  line  a  b.  Thus  line  a  b  may  be  stretched  at 
any  convenient  distance  within  reach  of  the  station-rods  described 
in  chapter  III.  The  center  line  of  the  machine  is  to  be  brought 
parallel  with  line  /  in,  which  in  turn  is  parallel  with  line  a  h  b, 
as  will  be  shown  later.  The  station-rods  /  and  g  are  placed  at 
right  angles  with  line  /  m,  with  one  end  of  each  rod  even  with 
the  center  line  of  the  machine  to  be  alined  or  squared  up. 


FIG.   111.— ALINING  SHAFTING  WITH  A  PLUMB-BOB. 

Place  the  body  in  such  a  position  directly  in  line  with  points 
a  and  b,  though  some  distance  beyond  either  one  of  these  points, 
that  the  eye  can  be  brought  to  a  position  something  as  shown  at  i, 
so  that  the  line  of  sight  i  h  brings  line  c  d  to  perfectly  cover  and 
hide  the  portion  of  line  a  -b  which  lies  between  c  a.  Thus  that 
part  of  the  line  at  h  n  is  entirely  hidden  by  a  portion  of  the  plumb- 
line  between  c  and  d.  Any  variation  of  the  eye,  even  the  one- 
hundredth  of  an  inch  will  bring  a  portion  of  line  a  b  into  view, 
indicating  at  once  to  the  observer  that  he  has  changed  his  position 
so  that  his  eye  is  no  longer  vertically  beneath  line  a  b. 

If  possible,  the  body  should  be  placed  against  a  wall  or  a  post 
when  in  position  at  /,  but  a  man  with  steady  nerves  can  stand  still 
enough  to  sight  the  lines  within  one-hundredth  of  an  inch.  Should 
it  be  necessary  to  work  with  great  exactness,  using  very  fine  lines, 


270  MILLWRIGHTING 

and  there  is  no  post  or  wall  handy,  secure  a  nail  keg  to  sit  upon, 
procure  two  strips  of  wood  from  3  feet  6  inches  to  4  feet  6  inches 
long,  drive  a  nail  through  both  pieces  close  to  one  end  (so  as  to 
make  a  pair  of  compasses  of  them),  then  spread  the  lower  ends 
of  the  strips  a  couple  of  feet  apart,  and  stand  them  on  the  ground 
in  front  of  the  person  as  you  sit  on  the  keg,  underneath  line  a  b. 
Place  the  upper  teeth  on  the  nailed-together  ends  of  the  sticks,  as 
shown  at  r.  Juggle  the  ends  of  the  sticks  on  the  ground  until  the 
eye  brings  the  two  lines  into  one,  as  described,  and  then  you  are 
in  position  to  do  some  fine  sighting  with  the  naked  eye,  which  can 
scarcely  be  excelled  by  the  transit. 

With  the  body  in  position  as  described  above,  the  two  lines 
will  appear  to  be  one,  as  at  o,  and  the  two  station-rods  will  appear 
as  shown  at  p  and  q,  the  marks  being  the  distance  the  new  machine 
center  is  to  be  located  from  the  line  a  b.  All  that  is  now  necessary 
is  to  move  the  new  machine  until  the  marks  p  and  q  are  hidden 
by  bob-line  o,  and  when  that  happens  the  new  machine  is  in  aline- 
ment  with  line  a  b.  To  the  man  who  has  never  worked  with  an 
arrangement  of  this  kind,  it  appears  as  if  the  whole  process  could 
be  much  simplified  by  hanging  a  second  plumb-bob  at  n.  The 
millwright  has  only  to  try  this  just  once  to  find  how  misleading  the 
idea  is.  Two  plumb-bobs  suspended  from  the  same  stretched 
line  are  about  the  hardest  things  to  bring  to  rest — and  to  keep 
there — that  can  well  be  imagined. 

Try  as  you  will  with  two  plumb-bobs  hung  from  the  same  hori- 
zontal line,  and  the  usual  condition  of  things  is  as  shown  at  k  I, 
where  both  bobs  are  hung  from  line  /.  Try  to  still  one  of  these 
bobs  and  you  start  the  other  to  swinging,  and  two  men  might,  in 
an  hour  or  two,  get  both  bobs  stilled,  but  that  they  would  stay 
so  is  another  thing.  Try  it  and  see  what  great  influence  even  the 
air  movement  caused  by  walking  past  one  of  the  bobs  has  on  the 
whole  combination.  Use  a  single  bob,  as  at  o,  and  even  when  there 
is  a  slight  breeze,  and  the  bob  is  doing  the  pendulum  act,  the 
observer  can,  with  considerable  exactness,  average  the  swing  of 
the  bob  and  make  his  observations  very  closely. 

If  there  is  very  much  wind,  all  stretched  line  and  plumb-bob 
operations  should  be  suspended  until  the  air  is  still.  True,  a  close 
approximation  of  a  plumb-line  can  be  obtained,  even  when  quite  a 
wind  is  blowing,  by  letting  the  bob  hang  in  a  bucket  of  water. 


SETTING  UP  MACHINES  271 

This,  however,  will  act  as  a  sort  of  dash  pot  and  prevent  swaying 
of  the  bob  and  the  line,  but  it  will  not  cause  the  bob-line  to  hang 
vertical — it  will  be  forced  out  of  plumb  by  the  wind  pressure. 
The  line  a  b  will  also  be  deflected  at  the  point  of  suspension  c  by 
wind  pressure  on  the  bob-line,  also  by  the  wind  pressure  on  line 
a  b  itself.  Thus,  do  the  line  work  on  a  still  day  or  it  will  not  be 
correct,  and  the  alinement  of  the  shafting  and  machines  will  be 
anything  but  accurate.  This  is  one  of  the  reasons  why  transit 
alinement  of  machinery  is  desirable — there  is  not  the  chance  of 
error  from  long  swinging  chalk  lines.  Even  when  very  fine  wire 
is  used,  the  error  by  air  deflection  may  be  considerable,  even  in  a 
building  which  seemingly  is  well  closed  in.  This  is  especially  true 
when  the  lines  are  necessarily  long. 

BELT  SHIFTERS  AND  SHIFTING. 

Shifting  belts  are  not  as  numerous  as  they  were  a  few  years 
ago.  Before  the  day  of  the  shifting  belt,  the  tightener  or  binder 
was  the  almost  universal  method  of  stopping  a  machine  or  a 
shaft — and  it  must  be  confessed  that  under  certain  conditions  the 
belt  tightener  is  still  a  very  desirable  appliance.  And  it  must 
further  be  confessed,  or  at  least  acknowledged,  that  the  shifting 
belt,  while  very  desirable  in  itself,  carries  with  it  that  which 
"queers"  the  whole  business — the  much  reviled  and  ever  despised 
loose  pulley. 

The  rim-friction  clutch  is  the  solution  of  the  shaft  and  machine 
stopping  and  starting  business,  and  to  a  great  extent  it  has  taken 
the  place  of  both  belt  tighteners  and  shifting  belts  as  well  as  with 
sliding  gears  and  cut-off  couplings.  But  shifting  belts  are  still 
much  in  use  and  will  continue  to  be  used  until  the  last  machinery 
owner  has  become  convinced  that  the  loose  pulley  and  the  shift- 
ing belt  are  costly  appliances  for  him  in  the  end,  though  their  first 
cost  is  less  than  that  of  the  good  friction  clutch.  A  poor  friction 
clutch  is  dear  at  any  price,  therefore  shifting  belts  continue  to  be 
used  and  the  millwright  must  continue  to  make  belt  shifters  to 
wear  out  the  belts. 

The  good  belt  shifter  will  not  touch  the  belt  except  during  the 
act  of  actually  shifting  the  belt  from  one  pulley  to  the  other. 
When  the  belt  is  on  the  tight  pulley,  as  well  as  when  on  the  loose 
pulley,  the  shifter  must  not  touch  the  belt  in  any  manner  what- 


272 


MILLWRIGHTING 


ever.  Never  place  a  belt  shifter  which  must  be  held  in  place  with 
a  pin  or  a  brace  in  order  to  prevent  the  belt  from  running  over 
upon  the  other  pulley.  The  belt  shifter  should  never  be  made 
to  do  duty  as  a  belt  guide  in  order  to  keep  the  belt  fair  on  pulleys 
which  have  been  mounted  on  shafting  out  of  alinement. 

Thus  the  proper  arrangement  of  the  belt  shifter  begins  with  the 
erection  of  the  shafting  and  the  placing  of  the  pulleys.  When  a 
belt  will  run  fair  upon  either  tight  or  loose  pulley  when  once 
placed  there,  then  the  belt  shifter  may  be  arranged,  but  unless  a 
belt  will  actually  run  fair  on  either  pulley,  then  never  apply  the 
belt  shifter  until  the  tracking  of  the  belt  has  been  corrected.  Then 
a  lever  arrangement  may  be  applied  for  forcing  the  belt  up  the 
crown  of  either  pulley,  but  there  the  shipper  should  cease  to  act. 
The  belt  after  having  been  forced  off  the  crown  of  one  pulley 
should  run  upon  the  crown  of  the  other  pulley  without  having  to 
be  forced,  or  even  helped  along  by  the  belt  shifter. 

THE  ORDINARY  BELT  SHIFTER. 

Nine  times  out  of  ten  the  average  millwright  will  cut  holes 
in  a  couple  of  pieces  of  board,  slip  a  bit  of  2x4-inch  scantling 
through  the  holes  and  nail  the  boards  in  position  to  hold  the  scant- 
ling under  the  leading  fold  of  the  belt  close  to  one  of  the  pulleys. 


FIG.   112.— THE  ORDINARY   BELT   SHIFTER. 

Fig.  112  shows  the  arrangement  as  usually  put  up,  the  2x4-inch 
bar  a  being  supported  in  the  guides  b  and  c.  The  pins  d  and  e 
prevent  too  much  movement  to  the  shifter-bar,  while  the  lag- 
screws  /  and  g  force  the  belt  along  when  the  bar  is  moved  endwise. 


SETTING  UP  MACHINES  273 

Thus  far  the  arrangement  is  fair,  though  it  would  be  better  to 
put  in  rods,  with  a  nut  above  and  another  nut  below  the  bar  as 
shown  at  h  and  i,  the  rods  being  filed  or  ground  smooth  and  not 
less  than  %  inch  in  diameter  to  prevent  cutting  of  the  belt. 

It  will  be  noted  that  the  lag-screws  /  and  g  are  quite  close  to 
the  edges  of  the  belt.  This  is  wrong.  There  should  be  more  than 
an  inch  more  width  between  guides  /  and  g  than  the  width  of 
the  belt  for  all  belts  narrower  than  four  inches,  and  an  increased 
amount  of  clearance  between  belt  and  guides  for  all  wider  belts. 
The  great  error  into  which  the  millwright  falls  in  erecting  a  belt 
shifter  lies  in  the  pin  k  and  the  extra  pin-hole  k,  into  which  pin  k 
is  placed  after  the  belt  has  been  shifted,  the  hole  then  coming  on 
the  front  side  of  board  b. 

These  pin-holes  and  the  pin  k  do  the  business  of  holding  the 
shifter  tight  against  the  belt  all  the  time,  the  pin  k  being  shifted 
as  required  from  one  hole  to  the  other.  The  lag-screws  /  and  g 
either  one  or  the  other,  are  always  bearing  against  the  edges  of 
the  belt  which  is  worn  badly  in  a  very  short  time.  The  pin  busi- 
ness k  is  undesirable  at  all  times  for  the  reason  that  it  forces  a  man 
to  go  to  the  shifter-bar  every  time  the  belt  is  to  be  moved  from  one 
pulley  to  the  other.  It  is  much  better  to  omit  the  pin  k  and  to 
put  on  a  shipper  handle  long  enough  to  reach  to  the  point  where 
it  is  most  desirable  to  operate  the  belt  shifter. 

A  shipper  handle  is  represented  at  /,  Fig.  112,  arranged  in  the 
manner  indicated  above.  The  handle  is  made  of  2x6-inch  stuff, 
spruce  or  Georgia  pine  as  the  lumber  happens  to  be  at  hand. 
The  lower  end  of  the  handle  is  tapered  to  about  2  inches  in  diam- 
eter, full  width  being  left  at  m,  tapered  again  to  about  4  inches 
at  ri,  where  it  is  bolted  to  some  solid  point  of  support,  a  4-inch 
carriage  bolt  being  put  through  the  end  of  the  handle  to  prevent 
splitting.  A  slot  is  made  in  the  handle  at  m,  and  a  bolt  or  a 
lag-screw  is  used  at  that  point  for  attaching  the  handle  to  the 
shipper-bar,  which  is  placed  midway  of  its  travel,  with  the  belt 
halfway  on  each  pulley ;  then  the  handle  is  placed  at  right  angles 
to  the  shipper-bar,  and  while  in  that  position,  the  hole  for  m  is 
marked  on  the  shipper-bar.  This  method  of  arrangement  provides 
that  the  lever  has  the  same  angularity  at  each  end  of  its  throw. 
A  support  o  is  then  placed  under  the  lower  end  of  the  handle,  and 
a  double  wedge  shaped  piece  p  is  adjusted  in  a  position  central 


274 


MILLWRIGHTING 


to  the  throw  of  the  handle  /,,  and  then  fastened  permanently  to 
support  o.  This  is  all  that  is  needed  with  a  properly  arranged 
belt  and  pulleys.  By  the  time  the  handle  has  been  moved  to  the 
point  k,  the  belt  has  been  forced  off  the  crown  of  one  pulley  and 
is  ready  to  climb  the  other  pulley.  The  wedge  p  prevents  the 
jarring  of  the  machinery  from  working  the  belt  shifter,  and  the 
tendency  of  the  handle  to  move  down  the  wedge  p  is  all  that  is 
needed  to  keep  shipper-pins  d  and  e  against  their  respective 
guides. 

ROPE  AND  ROD  SHIFTERS. 

In  some  instances,  it  is  not  well  to  cumber  floor  or  ceiling 
with  a  cage  of  scantlings  similar  to  that  shown  by  Fig.  112.  In 
such  cases,  the  rod  shifter  may  sometimes  be  used  to  advantage. 


FIG.   113.— ROD   BELT  SHIFTER. 


This  is  particularly  the  case  with  machines  driven  from  a  counter- 
shaft on  or  under  the  floor.  The  device  consists  merely  of  a  rod 
of  %  or  1-inch  round  iron  bent  to  the  shape  shown  at  a,  one  end 
of  the  bar  forming  the  shifter-pins  or  yoke  b,  the  other  end  being 


SETTING  UP  MACHINES  275 

bent  up  to  serve  as  a  handle  for  operating  the  device.  To  shift 
the  belt  it  is  only  necessary  to  throw  the  handle  d  to  the  position 
indicated  by  the  dotted  lines  at  e.  This  forces  the  belt  from  one 
pulley  to  the  other,  and  the  weight  of  handle  d  and  shifter-yoke 
b  holds  the  rod  on  whichever  side  of  the  vertical  center  it  may 
chance  to  be.  The  double  stop  /  prevents  undue  motion  of  the 
shifter  in  one  direction  or  the  other.  Taken  as  a  whole,  the  device 
is  a  very  cheap  and  efficient  one,  easily  made  and  adjusted.  It 
is  held  in  place  by  two  staples,  as  shown,  which  are  driven  into 
holes  bored  in  the  floor. 

DISTANT  CONTROL  BELT  SHIFTERS. 

It  often  happens  that  distant  control  is  required  of  a  belt 
shifter,  as  in  the  case  of  a  conveyor.  Belt  conveyors  200  to  300 
feet  long  should  be  provided  with  means  for  stopping  and  starting 
at  either  end  of  the  belt,  and  when  a  head-driven  conveyor  is  300 
feet  long  it  becomes  quite  a  problem  to  stop  and  start  the  mecha- 
nism from  either  end,  or  from  any  point  along  the  length  of  the 
conveyor.  When  the  machine  is  motor-driven,  the  problem  is  a 
simple  one,  and  switches  may  be  cut  in  at  as  many  points  along 
the  length  of  the  conveyor  as  desired,  the  wires  being  carried  from 
one  end  to  the  other  to  reach  the  switches. 

With  a  belt-driven  machine,  the  author  prefers  to  operate  the 
belt  shifter  by  means  of  ropes  or  wire  cables  which  pass  along 
the  entire  length  of  the  conveyor.  In  the  case  of  elevators  where 
trouble  was  anticipated  on  account  of  the  nature  of  the  material 
to  be  handled,  ropes  from  the  belt  shifter  at  the  top  of  the  elevator 
were  carried  to  several  points  along  the  elevator  so  as  to  reach 
the  machine  which  discharged  into  the  elevator ;  the  discharge  of 
the  elevator;  and  a  point  in  its  hight  where  a  cleaning  door  was 
located.  In  the  case  of  water-driven  factories,  the  rope  shifter 
has  been  made  to  take  the  place  of  a  safety  stop  by  its  being 
attached  to  the  water  wheel  gate  and  thence  carried  to  every  room 
in  the  mill,  thus  placing  the  stopping  and  starting  of  the  machinery 
under  the  control  of  every  authorized  man  in  the  mill. 

ROPE  CONTROLLED  BELT  SHIFTER. 

The  rod  shifter  illustrated  by  Fig.  113  lends  itself  very  readily 
to  rope  control,  as  obviously  it  is  only  necessary  to  form  an  eye  in 


276 


MILLWRIGHTING 


the  end  of  handle  d,  attach  ropes  leading  in  opposite  directions, 
and  the  belt  can  be  shifted  as  far  away  as  the  ropes  will  reach. 
By  passing  the  ropes  over  sheaves,  and  applying  a  weighted  ten- 
sion pulley  at  the  farthest  point  reached  by  the  ropes,  the  problem 
of  distant  belt  control  has  been  solved. 

Fig.  114  shows  several  ways  of  arranging  a  rope  control  which 
the  millwright  can  vary  to  suit  circumstances.  The  ordinary 
wooden  shipper-bar  a  is  fitted  with  a  pair  of  sheaves,  5  or  6  inches 


FIG.    114.— ROPE    CONTROLLED    BELT    SHIFTER. 

in  diameter,  placed  so  close  together  that  the  ropes  cannot  get 
out  of  the  grooves.  The  ropes  are  put  through  holes  bored  in  the 
guides,  and  a  knot  tied  in  each  rope-end  settles  their  fastening. 
From  an  inspection  of  the  apparatus  it  will  readily  be  seen  that 
upon  pulling  downward  upon  rope  e  the  shifter-bar  will  be  forced 
to  the  left,  and  contrariwise  upon  pulling  rope  d  the  pulleys  mov- 
ing with  the  shipper-bar  and  the  ropes  traveling  sidewise  a  dis- 
tance equal  to  the  travel  of  the  bar. 

So  far  the  matter  is  very  simple.    To  carry  the  ropes  to  the 


SETTING  UP  MACHINES  277 

places  from  which  it  is  desired  to  operate  the  belt  shifter,  sheaves 
are  placed  as  shown  at  h  and  i,  and  the  ropes  led  in  the  desired 
direction.  As  many  sheaves  may  be  used  as  is  found  necessary, 
but  if  sheaves  are  not  to  be  had,  the  millwright  can  get  along  with- 
out them  by  simply  hanging  up  the  rope  angles  as  shown  at  /  and 
k  by  means  of  short  ropes  attached  to  the  bends  and  looped  over 
lag-screws  let  into  properly  located  timbers.  This  forms  a  ten- 
sion ball-crank,  and  it  will  carry  the  rope  motion  around  almost 
any  angle  if  properly  proportioned  and  erected.  It  is  not  as  con- 
venient as  the  sheave,  but  it  enables  a  man  to  "get  there"  in  spite 
of  difficulties,  the  lack  of  proper  apparatus,  etc.  A  very  conve- 
nient way  of  arranging  a  sheave  substitute  is  shown  at  I,  where  a 
portion  of  a  loop  in  the  rope  is  served  with  stout  cord  or  wire,  and 
the  loop  hung  over  the  lag-screw  or  pin. 

It  is  desirable  that  the  ropes  terminate  in  vertical  lengths  in 
order  that  proper  tension  may  be  applied  to  hold  everything  tight 
at  all  times.  To  this  end,  it  is  a  very  convenient  way  to  weight 
both  ends  of  the  rope  with  a  box,  as  shown  at  m,  the  box  being 
clamped  to  the  ropes  at  either  end  as  shown,  and  being  placed  in 
a  level  position  when  the  shipper-bar  is  in  mid-stroke.  Inside  the 
box  m,  it  is  desirable  to  place  a  heavy  ball.  An  old  cannon  ball 
5  inches  in  diameter  makes  an  excellent  weight  for  a  6-inch  belt, 
while  for  a  10-inch  belt  a  7-  or  8-inch  cast-iron  ball  is  heavy 
enough  to  do  the  shifting  and  to  keep  the  rigging  tight  at  all  times. 

The  action  of  this  arrangement  is  very  simple.  To  shift  the 
belt,  it  is  only  necessary  to  take  hold  of  box  m  and  raise  the  right 
hand  end  far  enough  that  the  ball  rolls  to  the  left  end  of  that  "box. 
The  moment  the  box  passes  beyond  a  level  position,  the  ball  rolls 
to  the  left  end,  drags  the  rope  down,  and  pulls  shipper-bar  along 
until  pin  o  engages  guide  /,  and  the  belt  has  been  shipped  to  the 
other  pulley.  The  weight  of  the  ball  n  holds  the  shifter-bar  at 
all  times  against  the  shake  of  the  machinery.  If  it  is  not  possible 
to  obtain  a  cast-iron  ball  for  the  tension  box,  dry  sand  may  be  used 
instead.  Sand  will  do  the  work,  but  it  is  not  as  convenient  and 
requires  a  larger  box. 


CHAPTER  XV. 

BABBITTING,  SCRAPING  AND  LUBRICATING. 

It  is  the  present  practise,  almost  universally,  to  line  journal 
bearings  with  some  form  of  soft  metal,  usually  one  which  can  be 
replaced  by  casting  a  new  lining  of  fusible  alloy  without  removing 
the  journal  from  its  place.  For  heavy  work,  the  brass  and  bronze 
bearing  will  be  employed,  but  for  all  ordinary  journal  bearings, 
"babbitt''  metal  continues  to  be  used.  Even  high-grade  engines 
have  their  crank-pin  bearings  lined  with  babbitt  which  is  cast 
inside  the  brass  bearing  usually  found  in  that  part  of  an  engine. 
Babbitt  has  been  substituted  for  brass  for  the  reason  that  when  the 
wrist-pin  becomes  hot  enough  to  melt  out  the  babbitt,  the  engineer 
is  very  quickly  made  aware  of  the  trouble,  and  is  forced  to  shut 
down  the  engine  at  once.  Whereas  with  the  brass  crank-pin  bear- 
ing, running  the  engine  may  be  continued  with  a  red-hot  crank-pin 
bearing  until  the  pin  becomes  permanently  sprung  or  other- 
wise out  of  shape.  Thus  the  babbitt  wrist-pin  bearing  is  a  safety 
device  to  protect  the  engine  against  possible  neglect. 

"BABBITT"  AND  "BEST  BABBITT." 

So-called  "babbitt  metal,"  like  lubricating  oil,  is  a  pretty  hard 
proposition  where  a  selection  must  be  made,  as  there  are  about 
as  many  alloys  passing  under  the  name  of  babbitt  as  there  are 
makers  of  that  alloy.  John  Babbitt,  the  inventor  of  the  recessed 
box,  lined  it  with  a  fusible  alloy,  the  exact  composition  of  which 
has  been  lost,  but  it  was  probably  composed  entirely  of  copper  and 
tin,  in  the  proportion  of  tin  9  parts,  copper  1  part.  Since,  how- 
ever, antimony  has  been  added,  and  by  some  makers  the  copper 
has  been  replaced  by  zinc.  The  following  table  gives  the  results 
obtained  by  analyizing  many  bearing  metals  at  the  Pennsylvania 
Railroad  laboratory  at  Altoona,  Penn.  It  was  found  that  of  all 
the  bronzes  tested  that  containing  copper  77,  tin  8,  and  lead  15 
parts  wore  more  slowly  than  any  other  "bronze"  alloy,  and  this 

278 


BABBITTING,  SCRAPING  AND  LUBRICATING   279 


BEARING-METAL  ALLOYS. 


Trade  Name  of  Alloy. 

Copper. 

Tin. 

Lead. 

Zinc. 

Antimo'y 

Iron. 

Camelia  metal 

70  20 

4  22 

14  75 

10  20 

0  55 

Anti-friction  metal  .... 
White  metal    

1.60 

98.13 

87  92 

12  08 

trace 

Car-brass  lining     

trace 

84  87 

15   10 

Salgee  anti  -friction.  .  .  . 
1  Graphite  bearing-metal 
Antimonial  lead  

4.01 

9.91 
14.38 

1.15 
67.73 
80  69 

85.57 

16.73 

18.83 

2  Carbon  bronze  

75.47 

9.72 

14.57 

3  Cornish  bronze  

77.83 

9  60 

12.40 

Delta  metal  

92.39 

2.37 

5.10 

0  07 

*  Magnolia  metal  
American  Anti-friction 
metal 

83.55 
77  44 

trace 
0  98 

16.45 
19  60 

trace 
0  65 

Tobin  bronze 

59  00 

2  16 

0  31 

38  40 

0  11 

Graney  bronze 

75  80 

9  20 

15  06 

Damascas  bronze  

76.41 

10.60 

12.52 

6  Manganese  bronze  
6  Ajax  metal 

90.52 
81  24 

9.58 
10  98 

7  27 

Anti-friction  metal.  .  .  . 
Harrington  bronze  .  .  . 
Car-box  metal 

55.73 

0.97 

88.32 
84  33 

42.76 

trace 

11.93 
6  03 

0.68 

7  Phosphor  bronze  
sP.R.R.  "B"  metal..  .  . 
9  Babbitt  metal  (parts)  . 
Babbitt  metal  light  .  .  . 
Babbitt  metal  best  
"Babbitt  (parts)  metal 
best               .    . 

79.17 
76.80 
1. 

1.8 
3.7 

4 

10.22 

8. 
50. 
89.3 
88.9 

96 

10.61 
15.00 

5. 
8.9 
7.4 

8 

Another  "babbitt"  ... 
Brittania  

1.5 
1 

45.5 

85  7 

40.00 

2  9 

16. 

Brittania 

81  9 

1  9 

16  2 

Brittania 

2 

81 

1 

16 

Brittania 

4 

70  5 

25  5 

Brittania 

10 

22 

6. 

62 

11  Plate  pewter  
White  metal   bearings 
on  German  locomo- 
tives   

1.8 
5 

89.3 

85 

7.1 
10. 

French  white  metal 
h:d  

10 

65. 

25. 

French  white  medium 
French  white  soft  
French  white  very  soft 
English:  —  'Parsons".  . 
English:—  'Richards". 
English:—  'Babbitt". 
English:  —  'Fenton's"  . 
English  :  —  'French 
Navy"        

5.5 

2. 
4.5 
3.5 
5. 

7 

83.3 
10. 
12. 
86. 
70. 
55. 
16. 

7  5 

70. 
80. 
2. 
10.5 
23.5 

7 

27. 

79. 
87.5 

11.2 
20. 
8. 
1. 
15. 
18. 

English  :  —  "German 
Navy"        

7.5 

85. 

7.5 

Type  metal,  soft,  to  .  . 
Type  metal,  hard  
Ornamental  castings.  . 
12  Pattern  metal  .  . 

10. 

83. 
80. 
66.63 
10. 

17. 
20. 
33.33 
2. 

1  Contains  no  Graphite.  2  Contains  a  possible  trace  of  carbon.  3  Trace  of  zinc,  Iron 
and  Phosphorus.  4  Dr.  H.  C.  Torrey  says  this  analysis  is  erroneous  and  that  Magnolia 
metal  always  contains  tin.  6  Contains  no  Manganese.  6  Phosphorus  or  Arsenic  0.37. 
7  Phosphorous  0.94.  8  Phosphorous  0.20.  9  (In  parts  by  weight).  lo  (In  parts  by  weight). 
11  Bismuth  1.8.  12  Bismuth  6;  Brass  8. 


280  MILLWRIGHTING 

mixture,  known  as  "alloy  B,"  is  the  standard  bronze  bearing 
metal  for  this  railroad. 

It  should  be  noted  that  the  difference  between  ''bronzes"  and 
''babbitts"  lies  chiefly  in  the  reversal  of  the  quantities  of  copper 
and  tin  contained  in  the  alloy,  the  "bronze"  containing  about 
90  per  cent,  of  copper  and  10  per  cent,  of  tin,  while  the  "bab- 
bitts" contain  90  per  cent,  of  tin  and  10  per  cent,  of  copper. 
Thus  the  babbitt  metal  is  merely  an  inverted  bronze. 

From  the  above  tabulated  alloys,  the  millwright  may  select 
the  one  wrhich  seems  best  fitted  for  the  work  in  hand.  In  case 
that  it  is  necessary  to  make  up  a  babbitt  containing  copper — that 
is,  to  melt  the  ingredients  as  stated  in  the  table — care  must  be 
taken  to  heat  hot  enough  to  fuse  the  copper,  and  then  immedi- 
ately lower  the  temperature  as  soon  as  the  copper  is  melted,  in 
order  that  the  tin  and  antimony  may  not  be  oxidized. 

MAKING  BEARING-ALLOYS. 

Melt  the  copper  first,  then  add  the  antimony  and  tin,  with  the 
melting  pot  removed  from  the  fire  that  the  addition  of  the  anti- 
mony and  tin  may  reduce  the  temperature  of  the  molten  copper. 
A  method  used  by  some  manufacturers,  as  described  by  Joshua 
Rose,  is  as  follows : 

Melt  12  parts  of  copper,  then  add  36  parts  of  tin.  Then  add 
24  parts  of  antimony  and  36  parts  more  of  tin,  the  temperature 
being  lowered  as  soon  as  the  copper  is  melted  in  order  not  to 
oxidize  the  tin  and  antimony,  the  surface  of  the  bath  being  pro- 
tected (with  dirt,  sand  or  a  little  powdered  charcoal)  from  con- 
tact with  the  air.  The  alloy  thus  made  is  subsequently  remelted 
in  the  proportion  of  50  pounds  of  the  alloy  to  100  tin. 

Should  it  be  desired  to  ascertain  just  how  the  percentages 
exist  when  the  above  method  is  followed,  it  may  be  stated  as 
follows : 

Copper        12  parts, 

Tin  36      " 

Antimony    24      '' 

Tin  36      " 


Total,    _  108 

Remelting,   with   twice   tin  216 

Grand  total,  324 


BABBITTING,  SCRAPING  AND  LUBRICATING   281 

Then  there  will  be,  copper  12  parts,  tin  288  parts,  and  anti- 
mony 24  parts.  The  percentages  will  be: 

12-^324=  3.7  per  cent. 

288-^324=88.9     "       " 
24-1-324:=  7.4    "       " 

This  agrees  closely  with  the  tabulated  percentages  given  for 
"best  babbitt"  in  the  preceding  table. 

PREPARING  BEARINGS  FOR  BABBITTING. 

It  is  very  important  when  journal  bearings  are  to  be  lined  with 
soft  metal — especially  when  doing  repair  work — to  .make  sure 
that  the  castings  are  clean  and  dry.  Water  is  the  worst  enemy 
of  the  babbitting  mechanic.  A  drop  of  water  flashing  into  steam 
increases  its  volume  about  1646  times,  and  if  there  happens  to 
be  babbitt  metal  in  the  space  the  steam  desires  to  occupy  it  comes 
out  of  the  bearing  hot-foot  and  lodges  upon  the  first  surface 
encountered,  no  matter  whether  it  be  metal  or  flesh.  Therefore, 
take  care  that  there  is  no  water  in  cavities  to  be  filled  with  or 
reached  by  melted  lining  metal. 

Bearings  can  be  poured  smoother  and  with  less  danger  of 
ribs  and  ridges  when  the  metal  is  hot.  When  the  metal  surfaces 
are  heated  to  a  degree  of  temperature  just  below  the  melting  point 
of  the  soft  metal,  then  ideal  conditions  have  been  reached  and  the 
best  possible  box  can  be  poured.  Oil  in  a  bearing  does  no  harm. 
It  will  not  flash  into  steam  like  water,  and  in  some  cases,  pouring 
oil  into  a  damp  bearing  makes  it  possible  to  pour  the  bearing 
without  any  trouble  from  the  water  in  it. 

But  it  is  dangerous  to  attempt  to  pour  when  there  may  be 
water  present,  even  though  oil  be  used,  for  sometimes  when  there 
is  very  much  water  present  the  oil  remedy  is  not  powerful  enough, 
and  severe  burns  upon  hands  and  face  may  attest  the  throwing 
power  of  water  when  suddenly  flashed  into  steam  by  contact  with 
hot  lining  metal. 

It  is  the  only  safe  way,  to  clean  out  all  the  dirt  which  may  be 
contained  in  the  cavities  of  the  casting.  Blow-holes  are  the  worst 
to  contend  with,  for  no  one  can  tell  how  deep  they  are  or  how 
much  moisture  is  contained  in  them  and  hidden  from  sight.  All 
castings  which  can  readily  be  carried  should  be  placed  over  a  stove 
or  the  forge  fire  until  it  is  certain  that  all  water  has  been  driven 


282  MILLWRIGHTING 

off.  On  field  work,  the  writer  has  on  more  occasions  than  one 
built  a  fire  right  on  top  of  the  box  casting  and  fed  the  blaze  with 
shavings  and  kindling  wood  until  sure  that  all  moisture  had  been 
dried  off. 

DRYING  BEARINGS  WITH  GASOLINE. 

A  still  better  way  is  to  pour  some  gasoline  into  the  casting  and 
set  the  fluid  on  fire.  It  makes  a  hotter  fire  than  wood  and  finds 
every  hole  and  crack  in  the  casting,  and  besides  acting  as  fuel  to 
heat  the  bearing,  the  oily  nature  of  the  gasoline  helps  to  displace 
the  water  in  the  manner  described  for  oil,  though  in  a  lesser 
degree.  Use  plenty  of  gasoline  and  make  sure  that  it  is  so  con- 
fined that  it  cannot  run  into  something  which  will  burn.  Gasoline 
will  run  away  like  a  streak  of  lightning  and  it  will  carry  flame 
with  it,  therefore  make  sure  that  you  are  not  going  to  set  some- 
thing on  fire  when  you  use  gasoline  as  described. 

Another  danger:  sometimes  the  supply  of  gasolene  becomes 
exhausted  before  the  casting  has  been  sufficiently  heated,  and 
more  gasolene  must  be  added.  Here  is  where  danger  comes  in 
unless  proper  precautions  are  taken.  Then  the  whole  operation 
of  adding  gasolene  to  a  flame  becomes  as  harmless  as  pouring  ice- 
water  into  a  snow-bank.  To  begin  with,  never  pour  gasolene  into 
flame  from  a  can,  for  the  gas  which  forms  above  the  fluid  in  the 
can  is  sometimes  as  explosive  as  gunpowder,  and  when  it  ignites 
it  scatters  the  burning  gasolene  in  all  directions. 

Gasolene  will  burn  in  a  very  harmless  manner  when  properly 
handled ;  so  when  it  is  necessary  to  replenish  the  burning  fluid  in 
a  journal-box  casting,  just  pour  some  of  the  gasolene  in  a  tin 
or  in  a  cold  and  empty  babbitt  ladle,  ignite  the  fluid  in  the  ladle 
and  then  pour  it  into  the  burning  gasolene  in  the  bearing.  A  ladle 
makes  a  splendid  tool  for  handling  ignited  gasolene,  and  there 
is  not  the  least  danger  in  handling  that  lively  fluid  if  it  be  done 
as  above  described. 

COVERING  MANDRELS  WITH   PAPER. 

While  the  journal  bearing  is  being  dried  out,  get  things  all 
ready  so  that  the  bearing  may  be  poured  as  soon  as  the  gasolene 
flame  dies  out.  The  mandrel  upon  which  the  babbitting  is  to  be 
done  was  of  course  provided  before  the  gasolene  stunt  was  com- 


BABBITTING,  SCRAPING  AND  LUBRICATING   283 

menced.  Bearings  may  be  cast  direct  upon  the  shaft  which  is  to 
run  in  them,  but  it  is  better  to  have  a  mandrel  for  that  purpose. 
If  the  journal  must  be  used,  place  a  sheet  of  strong,  smooth  paper 
around  the  journal  so  the  babbitt  does  not  come  in  direct  contact 
with  the  metal.  This  is  also  excellent  practise  in  all  cases  where 
mandrels  are  used  for  babbitting  single  boxes.  Where  many  are 
poured  in  succession,  the  mandrel  becomes  heated  and  does  not 
chill  the  hot  babbitt,  hence  the  paper  becomes  unnecessary. 

When  poured  directly  upon  the  journal,  babbitt  pinches  the 
shaft  along  the  line  of  division  between  box  and  cap,  and  scraping 
is  necessary  to  make  the  journal  fit  the  box  after  the  lining  has 
been  poured.  The  thickness  of  paper  around  the  journal,  com- 
bined with  the  shrink  of  the  soft  metal,  relieves  the  journal  so 
that  on  rough  work  little  or  no  scraping  will  be  found  necessary, 
the  arrangement  of  the  liners  giving  all  the  adjustment  necessary. 
On  fine  work,  however,  scraping  will  be  necessary.  In  fact,  all 
fast  running  and  close-fitting  bearings  should  be  scraped  to  fit 
the  journal  which  is  to  run  in  it. 

PEENING  SOFT  LININGS. 

Sometimes  the  soft  lining  is  peened  to  make  it  tight  in  the 
casting.  When  babbitt  or  other  lining  metal  is  poured  into  a 
cold  casting,  the  lining  becomes  chilled  before  the  iron  casting 
becomes  heated;  therefore  when  the  soft  lining  finally  cools  it 
shrinks  away  from  the  casting  and  becomes  a  loose,  rattling 
nuisance  which  must  be  peened  to  make  tight  in  the  journal  bear- 
ing casting.  Heating  the  box  before  pouring  in  the  soft  metal 
lining  is  a  cure  for  looseness,  as  the  iron  casting  then  shrinks  with 
the  soft  metal  lining  on  cooling  and  holds  it  fast  when  cold. 

There  is  another  way  of  fastening  a  lining  tightly  into  a  cold 
casting  and  that  is  by  using  one  of  the  antimony  alloys  as  a 
lining.  Antimony,  when  alloyed  with  lead  and  with  some  other 
soft  metals,  loses  the  power  of  shrinking  during  the  freezing 
process,  and  like  water  expands  and  fills  the  casting  so  tightly 
that  there  is  no  rattle  or  looseness.  Therefore,  when  forced  to 
line  a  cold  bearing,  use  an  antimony  alloy.  It  is  for  this  pur- 
pose that  the  antimony  alloy  is  used  for  casting  printing  type. 
The  expansion  of  the  alloy  during  the  instant  of  solidifying  or 
freezing  causes  the  metal  to  expand  into  every  corner  of  the  mold, 


284  MILLWRIGHTING 

thereby  securing  the  extreme  sharpness  necessary  in  printing  type. 
The  same  is  true  with  the  antimony  alloy  in  the  journal  bearing. 

PUTTY  OR  CLAY  DAMS. 

To  make  the  bearing  ready  for  pouring,  secure  the  mandrel 
in  position  and  make  tight  around  the  ends  and  sides  of  the  jour- 
nal, either  with  putty  or  with  moistened  clay.  The  author  prefers 
glazier's  putty  made  of  whiting  and  linseed  oil.  When  putty  can- 
not be  obtained,  go  to  the  nearest  clay  bank  and  procure  a  supply 
of  that  matcria4  which  should  be  worked  between  the  hands  until 
free  from  lumps,  and  plastic.  It  is  very  seldom  that  clay  will 
cause  the  soft  metal  to  snap  or  sputter,  but  there  is  always  some 
danger  of  such  an  occurrence.  A  fragment  of  the  moist  clay 
might  work  through  and  fall  into  the  bottom  of  a  cavity  in  the 
bearing.  The  molten  metal  would  float  such  a  fragment  and 
eventually  land  it  at  the  top  of  the  bearing ;  still,  if  it  should  hap- 
pen to  be  cornered  in  a  pocket  and  the  water  contained  in  the 
clay  should  be  suddenly  driven  off,  there  would  be  an  explosion 
similar  to  that  when  the  hot  metal  encountered  water  in  a  damp 
bearing  casting.  If  glazier's  putty  be  used  for  stopping  openings, 
there  can  be  no  danger  whatever. 

In  making  tight  around  the  ends  of  a  box,  particularly  where 
there  is  considerable  space  between  the  casting  and  the  mandrel, 
ake  care  not  to  press  the  putty  into  the  lining  space.  Should  there 
be  1/4  inch  or  more  space,  some  wooden  heads  should  be  cut  out  to 
fit  the  mandrel  and  clamped  against  the  box  casting.  If  it  is  a 
repair  job  and  there  is  neither  time  nor  opportunity  to  fit  heads, 
then  rub  some  putty  into  small  cord,  say  %  or  14  inch  thick,  and 
wind  around  the  mandrel,  close  against  the  ends  of  the  box.  The 
cord  will  serve  as  heads  and  some  more  putty  daubed  on  the  coils 
will  make  everything  tight. 

FORMING  OIL-CHANNELS. 

Oil-channels  may  be  formed  in  the  lining  by  winding  a  small 
cord  around  the  mandrel.  The  cord  should  be  of  the  hard  spun 
variety  and  preferably  should  be  rubbed  smooth  with  putty  before 
being  wound  upon  the  mandrel.  Take  care  that  the  cord  is 
wound  on  in  the  direction  the  shaft  is  to  run.  It  does  not  work 
well  when  a  passage  must  carry  oil  against  the  rotation  of  a  shaft. 


BABBITTING,  SCRAPING  AND  LUBRICATING   285 

When  cap  and  box  are  to  be  poured  together,  cut  two  notches  in 
each  liner,  one  notch  at  each  end,  then  clamp  the  cap  in  place, 
taking  care  that  the  liners  are  fair  against  the  shaft  before 
tightening  down  on  the  cap-bolts. 

If  there  are  holes  in  the  cap  for  pouring  in  the  lining,  besides 
the  oil-hole,  then  proceed  to  fit  a  white  pine  plug  in  the  latter  hole, 
fitting  the  plug  tightly  against  the  mandrel  and  let  it  project 
through  the  hole  in.  the  cap.  After  pouring,  the  cap  may  be  easily 
removed  by  driving  a  cold-chisel  between  cap  and  box,  breaking 
off  the  metal  which  connects  the  cap  and  box  linings  through  the 
four  notches  mentioned.  These  notches  should  not  be  more  than 
%  inch  on  a  side,  and  the  section  of  soft  metal  lining  being  small 
is  easily  broken  by  driving  in  the  cold-chisel.  The  four  bits  of 
ruptured  metal  should  be  carefully  chipped  or  filed  off  smooth 
with  the  surfaces  from  which  they  project.  Next  drive  out  the 
plug  in  the  oil-hole  and  the  cap  is  ready  for  scraping  to  fit  the 
shaft. 

HEATING  BABBITT  METAL. 

Before  pouring  a  bearing,  it  is  very  important  that  the  babbitt 
metal  be  heated  to  the  proper  temperature.  This  may  be  roughly 
determined  by  inserting  a  bit  of  wood — white  pine  is  the  best,  but 
whitewood  or  a  similar  soft  wood  will  do — into  the  hot  babbitt 
and  noting  the  effect  upon  the  wood.  It  is  best  to  whittle  the  stick 
to  a  smooth  flat  surface  similar  to  the  little  paddle  used  for  stir- 
ring paint  or  hot  glue.  The  surface  of  the  molten  metal  should 
be  kept  covered  with  a  layer  of  charcoal  or  forge  dust  to  prevent 
oxidization  of  the  alloy.  If  no  charcoal  is  at  hand  use  floor  dust 
or  plain  dirt.  Thrust  the  whittled  stick  through  the  layer  of 
dust  on  top  of  the  hot  metal,  and  note  results  to  the  stick.  If  the 
metal  is  too  hot,  it  can  be  felt  to  be  boiling  around  the  stick  which 
will  be  charred  more  or  less,  or  not  affected  at  all,  according  to 
the  temperature  of  the  molten  metal. 

When  a  fierce  "boiling"  is  felt,  the  stick  trembling  in  the 
fingers,  and  smoke  rises  from  the  submerged  end  of  the  stick, 
then  it  is  certain  that  the  metal  is  too  hot.  When  there  is  scarcely 
any  trembling  to  be  felt  in  the  stick  while  it  is  immersed  in  the  hot 
babbitt,  then  the  alloy  is  probably  about  ready  to  pour.  Withdraw 
the  stick  and  note  its  condition.  Should  that  portion  which  went 


286  MILLWRIGHTING 

into  the  babbitt  be  charred  badly,  the  metal  is  too  hot.  If  the 
stick  is  not  colored  at  all,  and  metal  almost  adheres  to  the  stick, 
then  the  metal  is  not  hot  enough  and  it  will  not  flow  properly  if 
poured  at  that  temperature. 

When  babbitt  metal  is  at  the  right  temperature,  the  stick  will 
be  faintly  charred  after  being  immersed  three  or  four  seconds  in 
the  molten  metal.  Two  or  three  tests  will  blacken  the  stick  even 
when  the  metal  is  not  quite  hot  enough,  therefore  it  is  best  to 
whittle  a  new  surface  on  the  test-stick  after  each  immersion.  Take 
a  shaving  off  of  one  side  of  the  stick — that  is  enough ;  there  is 
no  need  of  whittling  all  four  sides  of  it — and  keep  the  stick  mov- 
ing sidewise  when  in  the  hot  metal.  Do  not  let  it  lie  in  one  place 
but  move  the  stick  around  to  stir  the  babbitt  and  to  bring  the  stick 
in  contact  with  hot  metal. 

POURING  SOFT  METAL  BEARINGS. 

It  is  not  good  to  heat  soft  metal  too  hot.  True,  it  can  be 
allowed  to  cool  to  the  proper  stick-charring  temperature,  but 
excessive  heating  is  apt  to  cause  a  loss  of  some  of  the  metals 
composing  the  alloy,  through  oxidization.  Zinc  is  easily  driven 
out  of  an  alloy  by  too  high  temperature  when  melting.  Lead  soon 
turns  into  oxide — dross — upon  exposure  to  the  oxygen  of  the  air 
when  melted,  and  the  higher  the  temperature  of  the  melted  metal, 
the  faster  it  will  be  rusted  out  by  exposure  to  the  air.  It  is  for  the 
purpose  of  preventing  this  loss  of  some  of  the  metals  that  the  sur- 
face of  the  molten  alloy  is  kept  covered  with  charcoal  or  dust,  to 
prevent  access  of  air  to  the  surface.  But  when  the  alloy  is  over- 
heated, then  oxidization  proceeds  much  more  rapidly  and  much 
metal  is  lost  in  a  very  short  time. 

When  ready  to  pour,  never  follow  the  practise  of  skimming  the 
surface  of  the  metal  until  it  is  clean  of  all  dirt  or  dross.  Instead 
of  skimming  the  surface,  allow  the  covering  to  remain  until  the 
ladle  is  in  position  to  pour.  Then  let  another  workman  place  a 
stick  or  a  poker  in  the  lip  of  the  ladle,  so  that  as  the  ladle  is  tipped 
up  to  pour,  the  covering  is  held  back  and  the  clean  metal  flows 
out  from  under  the  coating.  When  pouring  must  be  done  by  one 
man,  and  it  is  necessary  to  support  the  ladle  with  both  hands,  then 
a  small  nut  or  some  other  convenient  shape  of  iron  may  be  laid 
upon  the  covering  close  up  to  the  pouring  lip  of  the  ladle. 


BABBITTING,  SCRAPING  AND  LUBRICATING  287 

When  the  ladle  is  tipped  up,  the  bit  of  iron  forms  a  floating 
dam  which  effectually  prevents  the  covering  of  dirt  from  flowing 
out  of  the  ladle,  while  the  molten  metal  has  free  passage  under 
the  bit  of  iron.  Sometimes  it  is  necessary,  when  the  floating 
dam  is  used,  to  pour  off  a  bit  of  the  metal  before  pouring  into  the 
journal.  This  is  for  the  purpose  of  washing  away  any  pieces  of 
dirt  which  may  come  along  with  the  metal  before  the  floating  dam 
gets  fully  down  to  work. 

When  two  ladles  are  used,  and  this  is  usually  necessary,  each 
man  should  pour  a  bit  of  metal  into  the  other  fellow's  ladle  in 
order  to  clear  away  any  loose  bits  of  dirt,  as  above  noted.  When 
babbitt  metal  is  melted  in  a  pot,  the  alloy  may  be  dipped  out  with 
ladles  as  required  for  pouring,  and  before  dipping  the  ladle  into 
the  pot,  push  the  covering  to  one  side  with  the  ladle,  then  pass 
the  ladle  below  the  surface  of  the  alloy,  taking  care  that  the  ladle 
is  entirely  submerged.  Then  lift  the  ladle  out  quickly  and  an 
excess  of  metal  will  be  forced  up  by  and  above  the  ladle.  As  this 
excess  of  metal  flows  away,  it  forces  back  the  dirt  or  charcoal  cov- 
ering on  top  of  the  alloy,  and  the  ladleful  of  metal  comes  out  of 
the  pot  clean  and  shining  with  not  a  sign  of  dirt  visible. 

The  metal  must  be  poured  very  quickly  when  thus  dipped  up 
clean,  for  the  reason  that  oxidization  is  going  on  all  the  time,  from 
the  instant  that  oxygen  comes  in  contact  with  molten  metal  until 
the  metal  has  become  cold  again.  Therefore,  hasten  the  pouring 
operation  once  the  metal  is  heated  and  exposed  to  the  air  ready 
for  pouring.  And  when  you  do  pour,  see  that  the  metal  runs  into 
the  bearing  in  a  clean,  steady  stream  as  large  as  the  opening  will 
allow.  Never  falter  or  hesitate  during  the  pouring  operation.  If 
the  stream  be  stopped,  even  for  a  second,  a  line  across  the  surface 
of  the  bearing  will  indicate  the  hight  of  the  metal  in  the  bearing 
when  pouring  was  stopped  and  started  again. 

Usually,  one  side  of  a  bearing  is  poured  into  and  the  metal 
rises  along  the  other  side  of  the  shaft  until  the  cavity  is  full.  In 
pouring  a  bearing  of  this  character,  move  the  ladle  from  one  end 
of  the  bearing  to  the  other,  causing  the  stream  to  traverse  along 
the  slot,  thereby  keeping  the  babbitt  at  approximately  the  same 
temperature  in  all  parts  of  the  bearing.  When  two  ladles  are  used 
to  pour  from,  it  will  be  sufficient  to  pour  into  diagonally  opposite 
corners  of  the  bearing,  and  if  both  streams  be  poured  quickly,  the 


288  MILLWRIGHTING 

cavity  will  be  filled  before  the  metal  becomes  too  cold  to  flow  to 
the  corners. 

POURING  THIN  SOLID  BOXES. 

It  was  stated  above  that  the  temperature  of  the  alloy  when 
poured  should  be  just  high  enough  to  slightly  char  a  soft-wood 
stick.  This  is  a  general  rule,  and  by  following  it  the  millwright 
will  not  go  far  astray  on  ordinary  work.  But  there  are  excep- 
tions :  when  thin  solid  boxes  must  be  poured,  and  there  is  a  long 
narrow  or  thin  space  to  be  filled  with  soft  metal,  then  it  is  some- 
times necessary  to  pour  the  metal  hotter  than  described.  In 
extreme  cases,  the  author  has  been  obliged  to  pour  babbitt  metal 
at  nearly  a  red  heat,  but  such  cases  are  exceptional  and  can  only 
be  regarded  as  faulty  pieces  of  work  on  the  part  of  the  machine 
designer  to  be  gotten  along  with  as  best  one  may.  In  such 
cases,  the  metals  to  come  in  contact  with  the  soft  metal  should 
always  be  heated  as  much  as  possible  before  pouring  in  the  lining. 

When  a  ladleful  of  metal  fails  to  fill  a  box,  and  another  ladle- 
ful  is  not  at  hand,  do  not  try  to  fill  the  box  by  pouring  hot  metal 
on  top  of  the  cold,  for  it  is  very  seldom  that  such  a  course  results 
in  a  satisfactory  bearing.  Hot  babbitt  will  not  unite  with  or 
weld  itself  to  cold  babbitt  by  simply  pouring  one  on  top  of  the 
other ;  therefore,  should  a  man  fail  to  fill  a  bearing  when  pouring 
in  the  lining,  it  is  decidedly  the  best  practise  to  take  down  and 
chip  out  the  partially  filled  bearing,  set  it  up  again,  and  pour 
from  a  supply  sufficient  to  fill  the  bearing.  An  "instalment-filled" 
bearing  may  do  good  service  for  a  long  time,  but  the  chances 
are  that  it  will  come  to  pieces  inside  of  three  months,  even  if 
it  does  not  fail  within  three  days  after  being  put  to  work. 

SCRAPING  BEARINGS. 

To  make  a  first-class  job  of  babbitting,  there  is  no  escape 
from  the  scraping  operation.  Even  for  rough  work,  should  it 
be  possible  to  make  a  good  bearing  without  scraping,  a  better 
one  can  be  made  if  the  operation  of  fitting  the  bearing  to  the 
journal  be  carefully  followed  out.  It  used  to  be  necessary  to 
run  machines  for  a  time,  more  or  less  lengthy,  in  order  to  let 
that  machine  "find  its  bearings,"  so  that  it  would  not  heat  or 
work  the  bolts  loose  which  held  the  caps  in  place.  All  this  pre- 


BABBITTING,  SCRAPING  AND  LUBRICATING  289 

liminary  running  and  ''finding  its  bearings"  is  needless  when  the 
journals  are  properly  fitted  to  their  bearings.  When  a  shaft 
hits  a  bearing  only  in  two  spots,  at  opposite  sides  and  ends  of 
a  bearing,  it  cannot  be  expected  that  the  shaft  will  run  cool  and 
steady  in  that  bearing. 

When  a  shaft  is  made  up  in  a  bearing,  and  given  a  turn  or 
two,  and  you  find  black  spots  in  two  or  three  parts  of  the 
soft  metal  lining  with  no  marking  elsewhere,  then  it  is  sure  evi- 
dence that  the  shaft  touches  the  bearing  only  at  those  two  or 
three  spots.  The  remedy  is  to  remove  the  metal  at  those  points 
until  the  shaft  touches  at  four  or  five  places  instead  of  at  two  or 
three.  Next,  remove  the  four  or  five  and  secure  a  bearing  at 
eight  or  ten  places.  Continue  this  work  until  the  shaft  has  a 
bearing  in  many  spots.  By  carrying  the  spot  removing  to  a  great 
length,  innumerable  points  of  bearing  could  be  obtained  between 
the  shaft  and  the  soft  metal  lining,  and  it  could  be  assumed  that 
they  touched  each  other  at  all  points  and  that  the  contact  between 
them  was  practically  perfect. 

When  fitting  a  bearing  to  a  shaft  as  above,  the  high  blackened 
spots  are  commonly  removed  by  scraping,  hence  the  name  of  the 
operation  becomes  that  of  "scraping  a  bearing."  The  millwright 
may  do  a  very  good  job  of  fitting,  as  above  described,  by  the  use 
of  a  common  chisel — a  carpenter's  chisel,  commonly  known  as  a 
"firmer"  chisel.  With  this  tool  the  high  and  colored  spots  may 
be  removed,  and  a  little  plumbago  or  red  lead  mixed  with  oil 
and  rubbed  upon  the  shaft  just  before  it  is  each  time  tried  into 
the  bearing  will  leave  new  spots  for  the  millwright  to  scrape  off 
and  the  operation  may  be  continued  indefinitely,  or  until  a  bear- 
ing is  obtained  which  fits  the  shaft  with  the  requisite  nicety. 

TOOLS  FOR  SCRAPING  BEARINGS. 

The  carpenter's  chisel,  while  it  may  be  made  to  do  a  good  job 
of  scraping,  is  not  the  best  tool  for  that  purpose,  and  the  mill- 
wright should  add  to  his  kit  of  tools  two  or  three  good  scrapers 
for  this  purpose.  Fig.  115  represents  a  form  of  tool  commonly 
used  for  scraping  journal  bearings.  This  tool  may  be  forged  from 
any  convenient  bit  of  tool-steel,  or,  as  in  case  with  the  tool  illus- 
trated, it  may  be  made  from  a  worn-out  half-round  file.  The 
length  of  the  file  should  be  somewhat  longer  than  that  of  the  bear- 


290  MILLWRIGHTING 

ing  to  be  scraped  in  order  that  the  tool  may  be  held  easily  by  the 
hands,  one  end  of  the  tool  projecting  past  one  end  of  the  box 
while  in  use. 

To  scrape  a  box,  grasp  the  tool  with  the  thumb  and  ringers 
of  each  hand,  bring  the  sharp  edge  flat  against  the  box  lining  and 
shave  off  the  projecting  lumps  and  high  spots.  For  small  bear- 
ings, the  scraper  may  be  used  with  the  round  side  against  the 
soft  metal  lining;  but  when  a  bearing  of  large  diameter  is  to  be 
scraped,  the  flat  side  of  the  scraper  may  be  laid  against  the  work. 


FIG.    115.— SIDE  SCRAPER    FOR   JOURNAL  BEARINGS. 

For  rapid  wrork,  the  tool  shown  by  Fig.  116  may  be  used  to  advan- 
tage. This  tool  is  also  made  from  an  old  file,  but  in  this  case 
the  end  of  the  file,  not  its  side,  is  made  to  do  the  work. 

This  tool  is  also  a  home-made  affair,  and  almost  any  old  flat 
file  may  be  utilized  for  making  it — something  of  an  advantage 
when  it  is  considered  that  the  half-round  file  is  seldom  found 
around  a  plant,  while  the  flat  file  is  to  be  had  for  the  picking  up. 
But  there  is  quite  a  knack  in  making  the  end  scraper  so  that  it 


FIG.  116.— END  SCRAPER  FOR  FAST  WORK. 

will  do  fast  work.  There  are  two  things  which  make  this  scraper 
either  a  good  tool  or  an  exceedingly  bad  one.  These  things  are 
the  angle  at  which  the  end  of  the  tool  is  turned  and  the  level  to 
which  the  cutting  edge  is  ground.  These  things  the  millwright 
must  experiment  with  and  determine  them  for  the  work  in  hand, 
the  metal  to  be  cut  and  the  man  who  is  to  do  the  cutting. 

The  engraving  gives  approximately  the  angles  which  the 
author  has  found  best  fitted  for  a  universal  tool  of  this  character, 
though,  as  stated,  the  angles  must  be  varied  slightly  according 


BABBITTING,  SCRAPING  AND  LUBRICATING  291 

to  the  work  to  be  done.  The  angle  of  the  bend  at  a  is  approxi- 
mately 75  degrees,  and  the  bevel  b  is  about  35  degrees  with  the 
bent-up  portion,  or  about  40  degrees  from  the  body  of  the  tool. 
In  using  this  scraper,  the  handle  is  usually  lifted  more  or  less  out 
of  parallel  with  the  line  of  cut,  which  is,  of  course,  lengthwise 
of  the  bearing ;  hence  the  angle  of  40  degrees  may  be  reduced  as 
much  as  is  found  necessary  to  keep  the  tool  cutting  smoothly. 
Should  there  be  any  indication  of  chatter,  it  is  evidence  that  the 
tool  is  not  held  at  the  proper  angle,  which  should  be  changed 
until  the  scraper  cuts  smoothly.  As  merely  raising  or  lowering 
the  hand  changes  the  angle  of  cut,  the  change  may  be  made 
instantly  Lnd  without  the  necessity  for  grinding  or  honing.  Every 
scraper  should  be  kept  "razor  sharp"  when  scraping  is  to  be  done, 
for  good  work  cannot  be  done  easily  with  dull  scrapers.  Neither 
can  it  be  done  quickly  or  profitably  to  either  millwright  or 
employer,  unless  the  scraper  is  in  good  condition. 

AUTOMATIC  LUBRICATION. 

While  machinery  may  be  operated  in  good  shape  by  means  of 
periodic  lubrication,  the  oil  being  supplied  from  a  squirt-can 
"once  or  twice  in  a  while,"  it  is  conceded  by  authorities  that  auto- 
matic lubrication  absorbs  less  than  one-half  the  power  in  journal 
friction  that  is  used  up  in  driving  journals  under  squirt-can  lubri- 
cation. This  being  the  case,  it  is  profitable  to  secure  automatic, 
or  rather  continuous  lubrication  at  all  times  for  all  journal  bear- 
ings and  slides. 

When  we  speak  of  automatic  or  continuous  lubrication,  it  is 
understood  that  a  supply  of  oil  is  at  all  times  flowing  over  and 
between  the  running  parts  of  the  bearing.  The  chain  or  ring 
bearing  is  a  common  form  of  continuous  lubrication,  a  constant 
and  continuous  supply  of  oil  being  brought  to  the  bearing  and 
the  surplus  allowed  to  flow  away  again,  taking  with  it  the  worn 
out  oil  and  the  steel  and  soft  metal  particles  which  were  torn 
from  shaft  and  journal  during  their  travel  one  over  the  other. 

CHAIN  OR  RING  LUBRICATION. 

The  chain  and  the  ring  method  of  supplying  oil  to  a  bearing 
has  one  very  serious  defect  which  is  this :  the  spent  and  dirty  oil 
is  returned  again  and  again  to  the  bearing,  until  finally  the  oil  is 


292  MILLWRIGHTING 

so  loaded  with  foreign  matter  that  it  ceases  to  lubricate  even  as 
well  as  the  squirt-can  method  where  the  old  oil  and  worn  metal 
particles  are  once  in  a  while  washed  out  of  the  bearing  by  the 
flood  of  new  oil  occasionally  poured  in.  Thus  the  self-oiling  bear- 
ing should  have  the  old  oil  drained  out  and  new  oil  put  in  every 
few  weeks.  If  this  is  done,  there  will  be  fairly  good  lubrication 
at  all  times. 

Some  concerns  permit  their  oilers  to  flood  self-oiling  bear- 
ings, filling  them  with  oil  much  more  frequently  than  is  necessary, 
and  running  the  oil  reservoirs  over  nearly  every  time  they  are 
filled.  This,  to  a  certain  extent,  washes  out  the  worn  out  metal 
and  oil,  and  gives  the  bearing  a  new  lease  of  life.  But  the  method 
is  a  somewhat  costly  one,  as  well  as  exceedingly  dirty. 

A  CIRCULATING  OIL  SYSTEM. 

What  is  needed  to  secure  a  perfect  system  of  lubrication  is  a 
continuous  feed  arrangement,  either  sight  or  forced,  from  a  cen- 
tral reservoir,  the  oil  being  piped  to  each  bearing  in  such  a  manner 
that  the  flow  of  oil  ceases  when  the  motion  stops,  and  commences 
automatically  again  as  soon  as  the  machinery  begins  to  move. 
The  principal  elements  in  a  system  of  this  kind  are  found  to  be 
oil  pipes  connecting  each  bearing  with  a  reservoir  of  oil,  to  which 
flows  all  the  oil  from  each  bearing  in  the  mill,  but  passing  through 
a  good  oil  filter  \vhile  on  the  way  from  bearing  to  reservoir. 

All  the  metal  particles  and  other  foreign  matter  is  thus  removed 
from  the  oil  which  is  then  raised  from  the  reservoir  by  means  of 
a  small  pump,  a  certain  quantity  being  permitted  to  pass  through 
sight-feed  oil-cups  into  pipes  leading  to  the  several  bearings  in 
the  mill.  The  surplus  oil  which  is  raised  by  the  pump,  and  refused 
by  the  several  sight-feeds,  flows  back  again  into  the  reservoir 
from  which  it  again  and  again  passes  through  the  pump  as 
described.  When  the  machinery  stops,  the  pump  stops  also,  and 
lubrication  ceases  as  soon  as  the  small  quantity  of  oil  adjacent  to 
the  sight-feeds  flows  back  to  the  reservoir. 

The  oil  being  filtered  perfectly  clean,  there  is  nothing  to  stop 
up  the  sight-feeds  and  they  require  very  little  attention  after  hav- 
ing once  been  set  for  the  amount  of  oil  required  by  each  bearing. 
As  the  amount  thus  sent  to  each  bearing  is  always  to  be  an  excess 
of  the  quantity  required,  the  sight-feeds  are  easily  adjusted — 


BABBITTING,  SCRAPING  AND  LUBRICATING   293 

and  they  remain  in  adjustment  for  a  long  time.  This  system  is 
very  easily  applied  to  ring  or  chain  oiling  bearings,  nothing  being 
necessary  except  to  connect  the  supply  pipe  through  the  usual 
oil-filling  hole,  then  to  tap  in  an  overflow  or  return  pipe  by  means 
of  which  the  surplus  oil  is  carried  back  to  the  reservoir. 

To  connect  up  rigid  flat  boxes  and  that  style  of  bearings,  it  is 
necessary  to  pipe  the  oil  into  the  oil-hole,  then  add  a  drip  pan 
under  the  bearing  and  connect  each  drip  pan  with  a  return  pipe 
to  the  oil  reservoir  to  carry  back  the  surplus  oil.  Fast  running 
bearings  must  have  oil  collars  attached  in  order  that  the  oil  may 
not  run  along  the  shafts  and  sneak  away  past  the  added  drip  pans. 
But  as  most  machines  containing  fast  running  shafts  are  made 
with  the  necessary  oil  collars,  the  problem  in  that  direction  is  not 
a  serious  one. 

OIL  FILTERS  AND  PUMPS. 

There  are  numerous  oil  filters  in  the  market,  and  the  millwright 
will  not  find  it  a  paying  investment  to  try  to  make  up  one  of 
these  appliances,  though  he  may  find  it  profitable  to  add  a  steam 
coil  to  the  filter  in  order  to  lighten  the  oil  sufficiency  to  permit 
the  filter  to  remove  foreign  matter  to  better  advantage.  Very 
thick  oil  is  hard  to  filter.  When  thinned  by  heat,  it  passes  the 
filtering  medium  much  more  readily.  As  regards  oil  pumps, 
almost  anything  will  answer  which  can  raise  the  oil  from  the 
reservoir  to  the  sight  feeds.  The  author  prefers  a  small  centrif- 
ugal pump,  as  owing  to  the  absence  of  any  valves,  and  to  the 
submerged  or  flooded  position  of  the  pump,  it  never  fails  as  long 
as  the  belt  stays  on  the  pulleys.  When  direct-driven  by  a  small 
electric  motor,  the  arrangement  is  almost  an  ideal  one. 

OILS  AND  OIL  TESTING. 

The  millwright  need  not  spend  much  time  nowadays  testing 
oils,  for  the  chemists,  the  college  men  and  the  oil  manufacturers 
have  done  that  work  for  him,  and  they  have  done  it  so  well  that 
little  remains  for  the  oil  user  except  to  tell  the  oil  dealer  or  agent 
the  conditions  under  which  the  oil  must  do  service.  With  that 
information  in  full,  the  oil  man  can,  and  will,  select  an  oil  for 
the  consumer  which  will  do  all  that  is  required  of  it.  Sometimes 
it  is  necessary  to  make  a  change  in  the  oil  thus  selected,  but  it  is 


294  MILLWRIGHTING 

usually  because  the  conditions  were  not  fully  set  forth  to  the  oil 
dealer. 

In  the  olden  times,  when  the  millwright  got  along  with  tallow, 
whale  oil,  lard  oil  and  tar,  the  finding  of  a  suitable  lubricant  for  a 
high-speed  job  would  have  been  a  serious  matter  were  it  not  for 
one  thing  which  saved  the  situation.  That  one  thing  was,  there 
were  no  high  speeds !  Square  shafting  lumbered  along  at  100 
to  120  r.p.m.  Water-wheels  revolved  from  15  to  50  times  a 
minute,  and  steam  engines  were  running  very  fast  indeed  when 
the  crank  shaft  made  75  revolutions  a  minute. 

THE  GLASS  OIL-TEST. 

Then  when  it  was  necessary  to  compare  one  oil  with  another, 
a  clean  pane  of  glass  was  procured,  a  drop  of  each  oil  to  be  tested 
was  placed  close  to  one  edge  of  the  glass  with  an  inch  or  two 
between  the  drops  which  represented  the  various  kinds  of  oil. 
Then  the  glass  was  tilted  to  a  position  nearly  vertical,  and  the 
drop  of  oil  which  traveled  farthest  down  the  glass  was  declared 
the  best  oil.  Time  was  kept  on  the  progress  of  the  several  drops, 
and  the  one  which  went  the  farthest  in  a  given  time  was  named  as 
the  best  "high-speed"  oil,  while  the  one  which  did  not  move  out 
of  its  tracks  was  adjudged  the  best  form  of  grease  or  slush  for 
gears  and  heavy  shafts  revolving  in  wooden  bearings. 

As  a  refinement  of  this  method  of  oil  torture,  tests  were  made 
at  different  temperatures,  corresponding  to  the  different  seasons 
of  the  year,  and  in  that  way  the  millwright  worried  out  for  him- 
self a  set  of  standards  by  means  of  which  he  mixed  his  cow 
grease,  hog  lard,  and  whale  oil  in  varying  proportions  which  pre- 
vented the  too  frequent  squeaking  of  the  old-time  wooden  bear- 
ings, and  prevented  all  but  semi-occasional  mill  fires  from  hot 
bearings. 

When  mineral  oil  first  became  known,  chaos  reigned  indeed 
in  the  "department  of  lubrication"  and  fakirs  innumerable  sprang 
up  on  all  sides  to  the  despair  of  the  oil  user. 

AN  OIL-TESTING  MACHINE. 

But  things  have  changed.  Today  the  oil  agent  is  the  mill- 
wright's friend  and  can  help  him  out  of  many  a  trouble.  There 
are  but  very  few  oil-making  concerns  but  that  are  reliable  and 


BABBITTING,  SCRAPING  AND  LUBRICATING  295 

depend  upon  the  researches  of  their  chemists  for  the  quality  of 
the  oils  they  manufacture.  Oil  testing  no  longer  consists  of  a 
foot  race  down  a  pane  of  glass.  Instead  of  that  crude  method  of 
testing,  each  oil  is  placed  in  a  machine,  one  type  of  which  con- 
sists of  a  shell  clamped  over  a  cylinder.  Between  the  two  is 
placed  the  oil  to  be  tested,  the  shell  is  clamped  to  the  cylinder 
with  a  given  pressure  to  the  square  inch,  which  can  be  varied 
as  desired.  The  sleeve  is  prevented  from  revolving  by  a  weight 
like  a  pendulum,  placed  at  the  end  of  a  lever  which  in  turn  is 
attached  to  the  sleeve.  The  weight  and  the  distance  at  which  it 
is  supported  can  also  be  varied  at  will. 

The  cylinder  is  now  revolved  at  a  steady  speed,  which  can 
also  be  varied  or  changed  when  desired,  but  which  is  kept  con- 
stant at  a  predetermined  surface  velocity  during  an  oil  test.  The 
rise  in  temperature  of  the  cylinder  and  sleeve  is  also  carefully 
noted,  and  each  kind  of  oil  is  tested  out  under  different  speeds, 
various  pressures,  temperatures,  and  with  continuous  lubrication, 
intermittent  lubrication,  also  with  but  a  single  charge  of  oil  in 
the  test  machine,  which  is  run  until  the  known  weight  of  oil  con- 
tained in  the  machine  has  been  exhausted.  Thus  the  time  factor 
is  included  with  the  factors  of  speed,  pressure  and  temperature. 

In  this  manner,  each  variety  of  lubricating  oil  is  faithfully 
tested  out  and  its  capabilities  become  exactly  known.  The  oil 
dealer  places  this  data  before  the  millwright  or  the  oil  user  in 
the  shape  of  suggestions  as  to  which  oil  is  most  suitable  for  a 
given  set  of  conditions.  If  the  oil  man  is  not  given  a  knowledge 
of  all  the  conditions,  or  if  they  are  mistakenly  represented  to 
him,  then  it  is  impossible  for  him  to  name  the  particular  variety 
of  oil  best  fitted  for  the  particular  duty  the  machine  must  per- 
form ;  hence  the  occasional  necessity  for  a  change  of  oil  now  and 
then,  ever,  when  in  line  with  the  dealer's  suggestions. 

GREASE  LUBRICATING. 

Lubrication  by  means  of  grease  should  only  be  considered 
when  the  pressure  is  heavy  and  the  motion  slow.  Grease  is  not 
suitable  for  any  machinery  running  at  high  speed,  but  it  works 
well  on  rough  slow-moving  journals — and  on  fine  slow-moving 
ones  also.  For  elevators,  conveyors,  and,  in  fact,  for  all  jour- 
nals where  there  is  a  good  deal  of  dirt,  grease  lubrication  is  desir- 


296  MILLWRIGHT1NG 

able.  Albany  grease,  with  its  distinguishing  smell  of  prussic 
acid  (like  the  kernel  in  peach-stones),  is  not  usually  profitable 
as  a  regular  lubricant,  as  it  is  usually  rather  too  costly  for  that 
purpose.  But  on  journals  where  other  lubricants  fail,  and  in 
places  where  cost  of  lubricant  is  of  little  account,  then  albany 
grease  is  of  great  value. 

ALBANY  GREASE. 

This  substance  is  frequently  used  as  a  precautionary  or  reserve 
lubricant  to  come  into  action  automatically.  Albany  grease  is  not 
liquid  under  ordinary  running  temperatures,  and  a  cup  of  this 
material  screwed  into  a  hole  in  the  cap  of  a  journal  bearing 
should  be  fitted  with  a  copper  pin  or  wire  extending  through  the 
grease  in  the  cup  and  terminating  at  the  shaft  against  which  the 
copper  pin  has  a  bearing.  In  case  the  regular  lubrication  fails 
and  the  shaft  becomes  heated,  a  portion  of  the  heat  is  conducted 
along  the  copper  pin,  a  portion  of  the  albany  grease  is  melted 
and  runs  into  the  bearing,  thus  supplying  the  necessary  lubricant 
until  such  time  as  the  regular  lubrication  is  resumed. 

In  case  of  ordinary  grease  lubrication,  the  grease  should  be 
contained  in  a  screw  grease-cup,  and  by  screwing  down  the 
cover  of  the  cup,  a  portion  of  the  grease  is  forced  through  the 
regular  oil  passage  into  the  bearing.  It  would  seem  at  first  sight 
as  if  this  were  a  very  poor  method  of  lubricating,  but  upon  closer 
observation  there  appears  much  to  commend.  The  lubrication  is 
positive ;  the  grease  must  go  directly  into  the  bearing  as  it  can 
escape  in  no  other  way.  An  excess  of  grease  will,  if  forced  into 
the  bearing,  find  its  way  out  at  the  ends  of  the  journal,  and  form 
rings  or  ridges  around  the  shaft,  effectually  closing  the  openings 
to  the  entrance  of  sand  or  other  dirt  which  may  be  adjacent  to 
the  bearing.  Thus  the  grease-cup  protects  the  bearing  from  sand 
in  the  case  of  elevators  and  conveyors. 

A  quantity  of  grease  piled  up  at  the  ends  of  the  bearing  tells 
the  oiler  that  too  much  grease  is  being  used,  and  he  will  not  force 
through  as  much  on  his  periodical  oiling  trips.  The  worn-off 
metal  is  forced  out  of  the  bearing  with  the  grease  which  is  dis- 
placed daily  by  the  fresh  supply  from  the  grease-cup,  hence  the 
bearings  are  kept  clean  and  do  not  become  filled  up  with  worn-off 
shaft  or  babbit  metal.  Should  the  shaft  or  the  bearing 


BABBITTING,  SCRAPING  AND  LUBRICATING  297 

become  hot,  the  heat  will  be  communicated  to  the  grease  in  the 
screw-cup,  and  the  expansion  of  the  mass  by  heat  will  cause 
an  extra  portion  of  lubricant  to  flow  into  the  bearing,  thereby 
supplying  the  lacking  lubricant  and  cooling  the  heated  bear- 
ing to  normal  temperature.  Another  thing:  grease  lubri- 
cating prevents  the  waste  of  oil  so  often  seen  where  periodical 
or  squirt-can  lubrication  is  employed.  The  oiler  cannot  waste 
grease  unless  he  does  it  on  purpose,  for  he  cannot  pour  one 
drop  in  the  oil-hole  and  ten  drops  outside  of  the  hole  as  is  so 
often  done  when  chasing  the  squirt-can.  Taken  all  in  all,  grease 
lubrication  is  a  good  thing  for  slow-moving  machinery,  and  the 
millwright  is  safe  in  using  that  method  of  lubrication  on  all 
bearings  running  less  than  150  r.p.m. 

LUBRICANTS  FOR  DIFFERENT  PURPOSES. 

While,  as  stated,  the  advice  of  the  oil  man  can  usually  be 
safely  followed,  it  is  always  desirable  to  know  for  one's  self  what 
is  what  for  the  purpose  of  checking  the  oil  man  should  be  prove 
otherwise  than  honest,  and  for  holding  in  reserve  in  case  the 
oil  man  fails  to  show  up  and  the  millwright  must  depend  upon 
other  than  Standard  oil  products.  For  there  are  other  oils  than 
those  derived  from  petroleum,  and  their  proper  use  for  different 
kinds  of  service,  together  with  the  proper  place  for  other  lubri- 
cants, is  shown  in  the  following  table  by  Professor  Thurston, 
who  has  done  so  much  in  investigating  the  value  of  various 
oils: 

BEST   LUBRICANTS    FOR   DIFFERENT   PURPOSES. 

Low  temperatures. — Light  mineral  lubricating  oils. 

Very  great  pressures,  slow  speed. — Graphite,  soapstone  and  other  solid 
lubricants. 

Heavy  pressures  with  sloiv  speeds. — The  above,  and  lard,  tallow  and 
other  greases. 

Heavy  pressures  and .  high  speeds. — Sperm  oil,  castor  oil  and  heavy 
mineral  oils. 

Light  pressures  and  high  speeds. — Sperm,  refined  petroleum,  olive, 
rape,  cotton-seed  oils. 

Ordinary  machines. — Lard  oil,  tallow  oil,  heavy  mineral  oils  and  the 
heavier  vegetable  oils. 

Steam  cylinders. — Heavy  mineral  oils,  lard,  tallow. 

Watches  and  other  delicate  machinery.— Clarified  sperm,  neat's  foot, 
porpoise,  olive,  and  light  mineral  oils. 

For  mixture  with  mineral  oils,  sperm  is  best,  lard  is  much  used,  olive 
and  cotton-seed  are  good. 


298  MILLWRIGHTING 

COLD  TEST  OF  OILS. 

One  of  the  most  important  points  in  the  selection  of  oils  is  the 
temperature  which  the  oil  can  stand  and  still  remain  fluid.  The 
determination  of  this  property  of  oil  is  known  as  the  "cold  test" 
and  it  is  performed  as  follows :  A  glass  thermometer  is  procured 
for  use  as  a  stirring  rod,  and  the  sample  of  oil  to  be  tested  is 
cooled  until  it  freezes.  If  necessary,  the  oil,  placed  in  a  four- 
ounce  sample  bottle,  is  packed  in  ice  and  salt  until  the  oil  solidi- 
fies. Then  the  bottle  is  removed  from  the  cold  pack  and  the  oil 
allowed  to  soften,  stirring  constantly  with  the  thermometer. 

Close  watch  is  kept  over  the  oil  and  the  thermometer,  stirring 
and  mixing  constantly,  until  the  oil  will  run  from  one  end  of  the 
bottle  to  the  other,  The  temperature  indicated  by  the  ther- 
mometer when  this  is  the  case  is  taken  as  the  cold  test  of  the  oil. 


CHAPTER  XVI. 

STEAM  AND  WATER  PIPE-FITTING. 

When  it  is  necessary  to  lay  out  the  steam  piping  for  a  mill  or 
factory,  it  is  the  practice  of  the  author  to  commence  at  the  distri- 
bution end  of  the  system,  instead  of  at  the  boiler,  and  to  work 
back  from  the  pipes  to  each  machine,  increasing  the  size  of  the 
pipe  at  the  junction  of  each  additional  pipe,  until  they  have  all 
been  accounted  for  in  the  area  of  the  main  steam  pipe  from  or  to 
the  boilers. 

No  hard  and  fast  rules  can  be  given  for  the  laying  down  of 
steam  pipes,  and  it  will  be  best  to  present  certain  instances  from 
which  the  reader  may  note  the  principle  involved  and  calculate 
for  himself  in  a  similar  manner  any  system  of  piping  which  his 
work  calls  for.  A  skeleton  diagram  should  first  be  made,  some- 
thing as  shown  by  Fig.  117,  with  the  diameter  of  each  steam 
opening  plainly  marked,  and  the  manner  of  making  connection 
with  the  main  pipe  also  plainly  indicated. 


0                                                  I 

i 

m                               n 

d        <M  ,  " 

2 

Jl"     Jl"           [f 

^ 

-.    '        ' 

i" 

H'  H«             5 

|             q|                               >-| 

FIG.  117.— LAYING  OUT  A  STEAM  LINE. 


a,  1-inch    Injector. 

b,  1-inch  Steam   Pump. 

c,  1-inch    Blower. 

d,  4-inch    Engine. 

e,  %-inch   Kettle   Coil. 

f,  1-inch   Radiator. 

g,  %-inch   Steam  Jacket, 
h,  1-inch   Radiator. 

i,  11/2 -inch    Whistle, 

j,  1  %-inch   Dryer. 


k,    %-inch   Steam  Jacket. 

1,    %-inch   Test   Pump. 

m,?  Boiler  Connection. 

n,?   Boiler  Connection. 

o,?  Main   Steam   Pipe. 

p,   1-inch  Radiator. 

q,    %-inch   Steam   Coil. 

r,    %-inch   Steam  Jacket. 

s,  ?    Pipe   Junction. 

t,   2   inches   Extra   for  Increase. 


299 


300  MILLWRIGHTING 

Starting  at  the  point  farthest  from  the  boilers,  at  /,  it  is  found 
that  pipes  k  and  /  unite  in  a  common  lead  which  must  run  along 
without  increase  in  diameter  until  pipe  /  is  admitted.  The  first 
thing  is  to  determine  the  necessary  size  of  pipe  to  serve  pipes  of 
1/2  inch  and  %  inch  in  diameter.  From  a  table  of  standard  dimen- 
sions of  wrought  iron  pipe  it  is  found  that  the  area  of  a  y2-mch 
pipe  is  0.304  sq.in.  The  internal  area  of  a  %-inch  pipe  is  0.533 
sq.in.,  making  at  total  of  0.837  sq.in.  area  for  the  two  pipes. 
From  the  same  table  it  is  found  that  the  area  of  a  pipe  nearest 
and  larger  than  0.837  is  0.861,  which  corresponds  to  a  diameter 
of  1  inch.  Thus  the  pipe  from  the  junction  of  k  and  /  to  the 
point  where  pipe  /  enters  should  be  of  the  size  known  as  ''one- 
inch,  but  having  an  actual  inside  diameter  of  1.048  inches." 

A  very  elaborate  pipe  table  may  be  found  in  "Kent's  Mechan- 
ical Engineers'  Pocket-Book,"  therefore  a  pipe  table  will  not  be 
given  in  this  book.  The  catalogs  of  pipe  manufacturers  also  con- 
tain excellent  pipe  tables,  and  these  may  be  had  for  the  asking. 

The  pipe  j,  li/>  inches  in  diameter,  has  an  internal  area  of 
2.036  sq.ins.,  and  added  to  0.837,  the  area  necessary  is  found  to 
be  2.873  sq.ins.  As  there  is  nothing  in  the  table  between  l1/^ 
and  2-inch  pipe,  which  has  an  internal  area  of  3.356  sq.ins.,  it  is 
evident  that  ,2-inch  pipe  must  be  used  from  the  junction  of  /  to 
a  point  where  that  diameter  fails  to  accommodate  the  other  small 
branches  //,  g,  etc.  The  difference  between  the  required  area  and 
the  actual  area  is  3.356 — 2.873=0.483,  or  a  little  more  than  the 
area  of  a  i/^-inch  pipe,  hence  the  2-inch  pipe  is  not  large  enough 
to  accommodate  all  the  branches  up  to  and  including  branch  h. 

As  the  branches  up  to  /  aggregate  2.873  sq.ins.,  and  branch  h 
calls  for  0.861  sq.in.  more,  the  pipe  must  be  increased  to  an  area 
of  3.734  sq.ins.,  and  a  2V,-inch  pipe  with  an  area  of  4.78  sq.ins. 
is  required.  But  there  is  now  an  excess  of  area  equal  to 
4.78 — 3.734=1.046,  or  enough  to  more  than  take  care  of  the  0.533 
sq.in.  of  pipe  g.  But  there  is  not  enough  area  left  to  handle  pipe 
/,  which  increases  the  total  area  to  5.128  sq.ins.,  against  4.87  in 
the  2i/,-inch  pipe.  Therefore  another  increase  must  be  made. 

The  next  largest  pipe  is  3  inches  in  diameter,  and  has  an  inter- 
nal cross-sectional  area  of  7.383  sq.ins.,  leaving  7.383 5.128 

=2.255  sq.ins.  for  the  next  branch.  But  the  branch  /  happens  to 
be  a  large  one,  2  inches  in  diameter,  and  having  an  internal  area 


STEAM  AND  WATER  PIPE-FITTING  301 

of  3.356  sq.ins.,  or  more  than  the  excess  noted,  making  it  neces- 
sary to  increase  the  pipe  between  t  and  e  to  3%  inches  in  diam- 
eter, with  an  area  of  9.887  sq.ins.  The  excess  area  at  this  point 
is  1.403  sq.ins.,  which  more  than  accommodates  the  0.304  sq.in. 
of  branch  e,  the  area  called  for  being  4.788  sq.ins. 

The  next  branch,  d,  is  a  large  one,  4-inch  pipe  having  an  area 
of  12.370  sq.ins.,  and,  together  with  the  8.788  sq.ins.  of  area 
already  called  for,  requiring  21.158  sq.ins.  area,  or  a  pipe  6  inches 
in  diameter,  28.89  sq.ins.  area,  and  giving  an  excess  of  7.732 
sq.ins.  area.  But  at  this  point,  s,  another  pipe  comes  in,  and  as 
this  pipe  has  several  branches,  these  must  be  followed  up  to  ascer- 
tain the  size  of  the  pipe  which  will  supply  them. 

It  has  already  been  ascertained  that  a  %  and  a  %-inch  pipe 
together  require  a  1-inch  pipe  and  aggregate  0.837  sq.in.;  the 
1-inch  pipe  calls  for  0.861  sq.in.  more,  or  0.837+0.861=1.698 
sq.ins.,  making  necessary  a  1%-inch  pipe  to  s.  At  this  point,  we 
have  l!/o  and  6-inch  pipes  uniting,  but  we  will  stick  to  the  required 
area,  instead  of  to  pipe  diameter,  and  say  that  1.698+21.158 
=22.856  sq.ins.,  or  a  pipe  6  inches  in  diameter  is  still  large 
enough,  with  its  28.89  sq.ins.  area,  to  carry  both  branches  at  s 
and  some  distance  further.  The  blower  and  injector  pipes  c  and 
a,  each  1  inch  in  diameter,  call  for  a  1%-inch  pipe  to  the  point 
where  steam  pump  pipe  b  branches  out  from  a  2-inch  pipe  leading 
from  the  main.  The  three  pipes  a,  b  and  c,  aggregate  2.583  sq.ins., 
and  added  to  the  22.856  sq.ins.  called  for  at  ^  makes  a  total  of 
25.439  sq.ins.  of  pipe  to  be  supplied,  and  the  6-inch  pipe  will  still 
do  it.  There  now  remains  only  the  whistle  pipe  i,  1%  inches  in 
diameter,  and  calling  for  steam  area  of  2.036  sq.ins.  Add  this 
amount  to  the  25.439,  and  the  sum  total  is  27.475  sq.ins.,  still  less 
than  the  28.89  of  the  6-inch  pipe,  hence  that  size  of  pipe  may  be 
run  from  the  junction  of  pipe  d  right  to  the  boilers. 

But  at  the  boilers  another  problem  arises.  There  are  to  be  two 
boilers,  and  supposedly  both  are  to  be  used  to  supply  the  steam. 
In  that  case,  each  would  supply  one-half  the  volume,  and  a  pipe 
of  13.738  sq.ins.  area,  or  4  inches  in  diameter,  would  do  the 
work.  But  in  case  the  boilers  are  made  large  enough  so  that 
either  one  can  supply  the  steam  in  case  of  emergency,  then  it 
would  be  well  to  make  the  piping  larger  between  o,  m,  and  n. 

Six-inch  pipe  could  be  run  right  up  to  each  boiler,  but  the  cost 


302 


MILL  WEIGHTING 


of  a  6-inch  valve  over  each  boiler  would  be  considerable,  and  the 
millwright  will  probably  cast  about  for  some  means  of  reducing 
the  size  of  the  connections.  A  4-inch  pipe  will  supply  a  100  h.p. 
engine  at  the  high  pressure  commonly  used,  and  if  two  100  h.p. 
boilers  be  connected  at  in  and  n,  it  is  evidently  unnecessary  to 
provide  more  than  5-inch  piping  to  each  boiler,  thus  reducing 
the  cost  of  fittings  considerably.  It  is  also  possible  to  go  over  the 
steam  supply  pipes  and  pick  out  those  which  cannot,  or  will  not, 
be  used  at  the  same  time.  In  many  concerns,  there  are  numerous 
steam  using  machines  which  can  be  cut  out  during  a  pinch  for 
steam.  Thus,  in  some  seasons,  the  steam  radiators  are  not  used 
for  heating,  and  at  other  times  the  steam  jackets  are  not  needed. 
Should  it  be  possible  to  figure  the  pipe  and  fittings  in  this  man- 
ner, a  considerable  saving  may  be  made  by  cutting  down  the 
larger  pipes  a  size  or  two.  But  unless  the  millwright  be  fully 
conversant  of  every  detail  of  the  steam  consumption,  he  should 
go  very  slow  indeed  in  putting  in  connections  which  may  result 
in  wire-drawing  steam. 

"RULE  OF  THUMB"  PIPE  CALCULATIONS. 

The  method  given  above  for  calculating  the  sizes  of  pipes 
required  in  a  steam  distribution  system  requires  a  little  time  and 


FIG.  118.— THE  TRIANGLE  OF  PIPE  DIAMETERS. 


the  use  of  pipe  tables.     There  is  an  approximate  method  which 
gives  fairly  accurate  results  and  which   may  be   used  without 


STEAM  AND  WATER 'PIPE-FITTING  303 

tables  or  other  data.  The  method  in  question  is  known  to  the 
author,  as  the  "right  angle  method."  It  consists  of  laying  off  the 
diameter  of  a  pipe  on  one  leg  of  a  triangle,  as  at  a,  Fig.  118, 
where  a  portion  of  a  carpenter's  square  is  shown.  The  other  pipe 
is  laid  off  on  leg  b ;  then  the  diagonal  distance  from  one  leg  to 
the  other  between  the  two  points  will  be  the  required  pipe 
diameter. 

For  example :  let  it  be  required  to  find  the  diameter  of  a  pipe 
which  will  supply  two  branch  pipes,  one  4  inches  and  the  other 
3  inches  in  diameter  ?  Take  3  inches  on  leg  a,  4  inches  on  leg  b, 
then  measure  across  from  one  mark  to  the  other  with  a  rule  or 
scale  c,  and  the  distance  will  be  found  to  be  5  inches,  the  diameter 
of  a  pipe  which  will  supply  branches  of  3  and  4  inches  in  diameter. 

ANOTHER  OFF-HAND  METHOD. 

Even  when  a  carpenter's  square  is  not  at  hand,  the  millwright 
need  not  be  at  a  loss  to  determine  the  equivalent  of  pipe  diameters. 
Just  square  the  diameters,  add  the  squares  and  take  the  square 
root  of  the  sum.  In  this  case,  it  is  3X3=9,  and  4X4=16.  Then 
9-f-16=25,  and  the  square  root  of  25=5,  the  diameter  of  the  pipe 
which  will  supply  branches  of  3  and  4  inches  in  diameter. 

This  method  is  not  very  exact,  as  the  nominal,  instead  of  the 
actual  diameter  of  the  pipe  is  taken.  Take  the  case  of  a  %-inch 
pipe  and  a  %-inch  pipe,  say  pipes  k  and  /,  Fig.  117.  Here  we 
have  0.5X0.5=0.25,  and  0.75X0.75=0.5625.  The  sum  is  0.8125, 
and  the  square  root  is  about  0.9  inch.  As  there  is  no  pipe  of 
this  diameter,  we  must  take  a  1-inch  pipe  as  noted  when  the  pipe 
table  was  used.  Should  the  reader  use  the  actual  pipe  diameters, 
instead  of  the  nominal  diameters,  then  the  results  will  be  fairly 
accurate. 

NOMINAL  AND  ACTUAL  DIAMETERS  OF  PIPES. 

It  will  be  noted  that  the  actual  diameter  of  a  %-inch  pipe  is 
0.622  inch.  This  makes  quite  a  difference  in  the  capacity  rating, 
when  compared  with  the  nominal  diameter  of  0.5  inch.  .  Still  the 
method  is  very  useful.  For  instance :  how  many  1-inch  pipes  can 
be  supplied  by  a  4-inch  pipe?  4X4=16,  and  1X1=1.  Then 
lfr-=-l=16,  and  a  4-inch  pipe  will  supply  16  one-inch  pipes. 
The  scheme  is  very  useful  for  rough  calculating. 


304  MILLWRIGHTING 

It  is  to  be  regretted  that  steam  and  water  pipes  were  not 
brought  down  to  a  standard  of  even  inches  or  even  fractions  of 
an  inch.  With  a  %-inch  pipe  with  an  actual  inside  diameter  of 
0.27  inch,  and  an  8-inch  pipe  7.981  inches  in  diameter,  it  certainly 
is  pretty  hard  to  "know  where  you  are  at"  in  pipe  matters.  But 
as  there  is  no  prospect  of  any  change  in  pipe  dimensions,  wre  must 
make  the  best  of  it  as  we  find  things. 

SELECTION  OF  PIPE  AND  FITTINGS. 

Ordinary  or  standard  black  pipe,  from  %  to  1  inch  inclusive, 
is  butt  welded,  and  tested  to  300  pounds  to  the  square  inch.  Pipe 
l!/4  inches  and  larger  is  lap  welded,  and  proved  to  500  pounds 
to  the  inch,  and  the  millwright  should  keep  well  within  these 
figures  when  handling  steam  or  water  under  heavy  pressures. 
There  is  also  made  and  sold  from  stock  a  heavier  pipe  known  as 
"hydraulic."  This  pipe  should  be  used  when  very  heavy  pressures 
are  to  be  resisted,  particularly  when  there  are  shocks  similar  to 
those  when  the  hydraulic  ram  is  used. 

EASTERN  AND  WESTERN  STANDARDS. 

Pipe  fittings  and  threads  are  at  present  made  to  two  standards, 
the  Eastern  and  the  Western.  There  is  not  much  difference 
between  the  two,  yet  there  is  enough  so  that  the  pipe  and  fittings 
will  not  interchange  with  each  other  with  the  certainty  of  making 
a  tight  job.  The  author  has  frequently  been  put  to  great  trouble 
by  these  duplicate  standards,  particularly  when  erecting  in  the 
West  a  lot  of  pipe  sent  from  the  East.  The  pipe  tools  purchased 
in  the  West  at  a  local  dealer's  would  not  fit  the  pipe  threads  or 
the  fittings,  and  endless  trouble  was  encountered  from  this 
cause. 

The  best  way  out  is  for  the  millwright,  when  purchasing  a  set 
of  pipe  threading  dies,  to  obtain  a  set  of  adjustable  dies.  Then 
the  matter  can  be  handled  as  desired,  the  dies  set  to  fit  the  pipe 
threads  sent  out  in  the  fittings,  and  there  will  be  little  trouble 
unless  holes  have  to  be  tapped  with  locally  purchased  taps.  Even 
then  there  is  a  remedy,  for  a  pipe  tap  tapers  %  inch  to  the  foot, 
and  it  can  be  run  into  the  work  until  it  fits  the  thread  sent  out  with 
the  pipe. 


STEAM  AND  WATER  PIPE-FITTING  305 

STANDARD  PIPE  FITTINGS. 

There  is  no  reason  why  pipe  heavier  than  "standard"  should 
be  used  in  ordinary  power  plants,  as  such  pipe  is  ample  to  carry 
any  pressure  up  to  250  pounds,  but  heavier  fittings  should  be  used 
for  such  pressures,  and  the  threads  will  cover  greater  length  on 
the  pipes  when  "extra  strong''  fittings  are  used. 

When  it  comes  to  flanged  pipe  and  fittings,  there  are  two 
recognized  standards.  One,  for  pressure  up  to  125  pounds,  was 
adopted  by  a  joint  committee  of  The  American  Society  of  Mechan- 
ical Engineers,  The  Master  Steam  Fitters  Association  and  the 
Manufacturers.  The  other  standard  for  pressures  up  to  250 
pounds  was  adopted  by  the  Manufacturers  on  June  28,  1901,  and 
is  known  as  the  Manufacturers'  Standard. 

Flanged  fittings  are  also  made  in  three  weights  by  some  manu- 
facturers, and  are  designed  for  pressures  of  50,  125  and  250 
pounds.  The  millwright,  when  selecting  flanged  fittings,  should 
see  to  it  that  the  50-pound  weight  is  not  worked  off  upon  him 
when  the  125  or  standard  weight  is  necessary.  But  as  the  thin 
flanges  rarely  are  used  on  fittings  less  than  12  inches  in  diameter, 
there  is  not  as  much  danger  in  that  direction  as  might  be  expected. 
Some  manufacturers  list  their  pipe  and  fittings  as  "standard." 
for  pressures  up  to  125  pounds;  "full  weight,"  for  pressures 
between  125  and  175  pounds,  and  "extra  heavy,"  for  pressures 
higher  than  175  pounds. 

STANDARD  VALVES. 

Flanged  valves  are  made  with  corresponding  thicknesses  of 
flange  as  compared  with  thickness  of  pipe  flange,  and  may  be 
selected  accordingly  for  different  pressures.  All  weights  of  valves 
are  made,  and  the  "standard,"  "medium,"  and  "extra  heavy"  cor- 
respond to  the  standard  and  heavy  pipe  weights,  with  the 
"medium"  thrown  in  between.  Then  there  are  several  types  of 
valves  which  the  manufacturer  says  little  about,  but  fills  orders 
with  them  when  he  is  forced  to  do  so. 

A  manufacturer  of  valves  will  give  an  outfit  exactly  according 
to  the  price  paid  for  it.  A  good,  durable  1-inch  globe  valve 
weighs  nearly  four  pounds.  Yet  there  are  1-inch  globe  valves 
which  weigh  only  1%  pounds  complete.  These  valves  are  known 
to  the  trade  as  "competition  valves,"  and  are  pretty  good  valves 


306  MILLWRIGHTING 

(if  you  can  screw  them  on  without  squashing  them)  until  you  try 
to  close  one  against  pressure.  Then  there  is  trouble.  There  is 
not  enough  metal  in  the  valve  to  give  the  necessary  rigidity,  the 
metal  springs  out  of  shape  and  stays  there,  and  the  valve  can  never 
be  made  tight  under  pressure  for  the  reason  that  the  metal  springs 
away  as  fast  as  a  new  surface  is  ground  to  a  fit. 

When  selecting  valves  by  competitive  bidding,  insist  that  each 
bidder  designates  the  weight  of  each  size  of  valve  he  proposes 
to  furnish.  Never  permit  a  light-weight  valve  to  be  worked  off 
upon  you  and  there  will  be  little  trouble  from  leaky  valves, 
whether  globe,  gate,  plug  or  check.  Cut  down  cost  in  other 
directions  if  necessary,  but  do  not  try  it  on  pipe  fittings  and  valves. 
They  must  be  of  the  best.  If  you  buy  a  cheap  belt,  you  can  favor 
it  and  repent  at  leisure  until  the  belt  is  worn  out.  But  buy  a  cheap 
valve  and  you  are  "up  against  it"  every  time  that  valve  must  be 
used,  and  in  case  of  emergency,  it  is  likely  to  cost  more  than  the 
extra  price  of  first-class  valves  and  fittings  for  all  parts  of  the 
factory. 

PIPING  FOR  SERVICE  OR  FOR  PROFIT. 

There  are  two  methods  of  laying  out  a  pipe  system,  one 
method  is  from  the  standpoint  of  the  operating  engineer,  for  con- 
venience and  safety,  economy  of  operation  and  freedom  from  re- 
pairs and  renewals.  The  other  method  of  laying  down  piping 
sacrifices  everything  to  first  cost  of  the  material.  To  illustrate: 
The  author  has  personally  known  the  manager  of  a  contracting 
concern  to  force  his  draftsman  to  cramp  an  engine  room,  cause 
complications  in  the  factory,  and  generally  cramp  things  for  the 
simple  reason  of  limiting  the  distance,  and  the  length  of  steam 
pipe  between  boiler  and  engine,  to  16  feet !  This  manager  was 
bound  to  save  in  the  cost  of  three  or  four  feet  of  4-inch  black  pipe, 
even  if  the  entire  factory  suffered  from  the  uncalled  for  economy. 
Too  much  of  this  "fiat  saving"  is  done  by  contractors  at  the  cost 
of  many  times  the  original  saving  in  cost  of  operation  of  the  plant, 
or  in  repairs. 

When  pipe  systems  are  laid  out  by  the  contractor's  method, 
no  attention  is  paid  to  convenience.  Pump,  injector  and  heater 
are  placed  where  they  may  be  connected  by  the  fewest  possible 
feet  of  pipe  and  the  least  number  of  fittings.  Not  a  union  or  an 


STEAM  AND  WATER  PIPE-FITTING  307 

extra  tee  is  placed  in  the  piping  except  where  it  cannot  be  avoided. 
If  necessary  t.o  take  down  a  portion  of  the  piping  to  repair  a 
frozen  pipe,  there  is  no  union  to  be  disconnected,  or  a  "right  and 
left"  to  permit  easy  repairs.  Either  the  piping  must  be  taken 
down  for  many  feet,  from  a  distant  dead-end,  or  the  pipe  must  be 
cut  and  a  union  purchased  and  put  in  when  the  pipe  is  made  up 
again. 

A  tee  and  a  plug  cost  a  little  more  than  an  elbow,  but  the 
increased  cost  is  as  nothing  compared  with  the  saving  when 
another  bit  of  piping  must  be  cut  into  the  existing  layout.  Unions 
or  right-and-left  couplings  placed  in  a  few  convenient  places  will 
save  many  dollars  in  a  single  rush  job  of  repairing  or  in  making 
additions.  Above  all,  call  for  and  specify  pipe  and  fittings  which 
will  stand  up  under  the  pressure  to  be  carried.  Valves  which  will 
not  stand  grinding  in  are  utterly  worthless.  If  there  is  sufficient 
well  distributed  metal  in  a  valve  it  can  be  made  tight  by  regrinding 
many  times  and  will  last  half  a  lifetime. 

•LAYING  OUT  PIPING. 

When  a  job  of  piping  is  to  be  done,  no  matter  how  small,  it  is 
time  saved  to  put  it  upon  paper  at  once.  No  matter  whether  it 
be  a  single  pipe,  valve  and  elbow,  if  the  dimensions  are  laid  down, 
each  piece  may  be  cut  to  the  right  length,  and  everything  will  go 
together  without  a  single  "cut  and  try"  being  necessary,  and  with- 
out spoiling  one  or  two  pieces  of  pipe  by  cutting  it  too  short.  In 
laying  down  pipe,  first  find  the  length  of  the  center  lines  as  in  Fig. 
119,  sketch  A,  in  which  the  lengths  of  pipe  are  found  to  be  10 
feet  6  inches,  2  feet  1  inch,  3  feet  Tl  inches  and  20  inches  long, 
respectively. 

Next,  the  several  valves,  elbows,  tees,  couplings,  etc.,  are  laid 
down  upon  the  sketch,  as  shown  at  B,  conventional  signs  being 
used  for  the  various  fittings.  In  sketch  A,  risers,  indicated  by  r, 
are  twisted  around  90  degrees  so  as  to  appear  upon  the  plane  of 
the  drawing.  In  sketch  B,  risers  are  indicated  by  a  small  circle 
as  at  f.  Different  concerns  have  different  conventional  symbols 
for  representing  fittings.  In  sketch  B,  the  signs,  ordinarily  used 
without  any  reference  letters,  represent  the  various  fittings  as 
follows : 


308 


MILLWRIGHTING 


a,  Globe  valve.  g,  Elbow. 

b,  Cross.  h,  Check  valve. 

c,  Gate  valve.  i,  45-degree  elbow. 

d,  Tee.  p,  Pipe. 

e,  Plug  valve  or  cock.  u,  Union. 
/,  Riser.  B,  Boiler. 

In  the  illustration,  sketch  B,  the  risers  being  indicated  by  a 
small  circle,  there  is  no  opportunity  for  indicating  the  amount 
of  pipe  in  the  risers  or  the  fittings  placed  along  their  lengths, 


FIG.  119.— LAYING  OUT  PIPING. 

hence  a  plan  and  an  elevation  are  really  necessary  for  actually 
obtaining  the  working  lengths  of  the  pipe  on  a  job.  There  is 
another  method  of  representing  a  pipe  layout,  which  is  very  con- 
venient, but  which  is  often  side-stepped  by  the  millwright  on 
account  of  its  seeming  complications,  when  really  this  method  is 
more  simple  and  much  easier  to  comprehend  than  the  combined 
plan  and  elevation  method. 

PERSPECTIVE  PIPE  LAYOUT. 

As  shown  by  Fig.  120,  pipes  extending  in  any  direction  may 
be  laid  down  to  scale  and  actually  measured  upon  a  single  draw- 
ing. This  method  of  representing  pipes  is  called  "isometrical 


STEAM  AND  WATER  PIPE-FITTING  309 

projection,"  and  the  angles  used  are  vertical  for  the  vertical  pipes 
and  30  and  60  degrees  from  the  horizontal  for  pipes  leading  in 
the  other  directions. 

In  this  method  of  laying  down  pipe,  each  valve  or  fitting  is 
drawn  with  just  detail  enough  to  permit  it  to  be  recognized. 
Thus  the  globe  valve  a  is  readily  distinguished  from  the  gate  c, 
the  check  valve  h,  or  the  plug  cock  e.  Also,  the  tee  d  is  readily  dis- 


FIG.   120.— PIPE   SHOWN   IN  ISOMETRIC  PERSPECTIVE. 


tinguished  from  the  elbows  g,  g.  But  one  thing  in  particular 
should  not  be  omitted.  In  all  three  drawings,  A  and  B,  Fig.  119, 
and  in  Fig.  120,  figures  are  placed  adjacent  to  each  piece  of  pipe, 
indicating  the  diameter  of  pipe  to  be  used. 

In  some  layouts  it  is  well  to  use  the  conventions  shown  at  C, 
Fig.  119,  where  main  lines,  return  lines  and  drips  are  indicated 
by  the  whole  lines  /,  dotted  lines  m,  or  the  broken  lines  n,  respec- 
tively. 

MEASURING  PIPE  LINES. 

In  measuring  existing  lines,  or  in  taking  measurements  for 
new  piping,  always  work  from  center  to  center  of  the  different 
pipes.  Thus  in  measuring  for  the  10  feet  6  inches  of  pipe  shown 
in  Fig.  119,  measure  from  the  center  of  pipe  f,  sketch  B,  to  the 
center  of  g.  When  the  lengths  of  the  pieces  forming  this  pipe 
are  to  be  cut  off,  measure  from  the  center  of  f  to  the  center  of  a 
for  one  length,  and  from  centers  of  e  and  g  for  the  other  length. 


310  MILLWRIGHTING 

In  cutting  pipe  to  fit  these  measurements,  allowance  must  be 
made  for  the  dimensions  of  the  several  fittings  which  are  to  make 
up  a  portion  of  the  total  length  of  pipe  between  measuring  points. 
Thus  it  is  necessary  to  work  to  the  actual  dimensions  of  the 
fittings  in  order  that  the  over-all  dimensions  of  the  pipe  lengths 
may  be  obtained.  In  laying  down  pipes  on  plans,  and  in  taking 
off  quantities  from  drawings,  the  length  of  each  fitting  must  be 
determined,  then  about  1  inch  allowed  for  the  projection  of  each 
thread  into  its  fitting,  and  the  lengths  of  the  several  pipes  worked 
up  in  that  manner.  When  making  lists  of  pipe  and  fittings, 
particularly  for  large  or  medium  sized  jobs,  it  is  well  to  follow 
the  same  plan  as  described  for  listing  power  transmission  mate- 
rial, on  page  197,  chapter  XII,  making  the  first,  or  erector's 
list  exactly  as  the  pieces  are  found  upon  the  drawing,  then  com- 
piling and  adding  like  pieces  in  exactly  the  same  manner  that  the 
buyer's  list  was  worked  up  as  described  in  chapter  XII.  In  fact, 
if  an  erector's  list  and  a  buyer's  list  is  made  of  the  pipe  laid  down 
upon  the  drawing,  there  will  be  no  errors  in  purchasing  and 
checking  the  fittings,  and  no  trouble  in  putting  them  in  place  in 
accordance  with  the  drawings. 

CUTTING  OFF  PIPE. 

In  cutting  off  pipe,  the  tools  available  must  of  course  be  used, 
but  there  are  many  things  which,  if  neglected,  go  to  make  the  job 
a  poor  one.  Beyond  all  doubt  the  best  way  of  cutting  off  pipe 
is  with  a  cutting-off  tool  in  a  power  machine,  which  actually  cuts 
out  a  y±  or  %-inch  chip.  This  method  of  cutting  does  not  raise  a 
bur  in  the  end  of  the  pipe,  and  when  a  dull  wheel  tool  is  used, 
the  bur  becomes  so  pronounced  as  to  seriously  reduce  the  internal 
area  of  the  pipe.  In  any  case,  where  a  wheel  cutting-off  tool  is 
used,  the  workman  should  be  provided  with  a  reamer  by  means 
of  which  the  bur  may  be  removed  to  the  full  area  of  the  pipe. 
This  should  not  be  overlooked,  for  the  reduction  of  area,  particu- 
larly in  small  pipes,  sometimes  seriously  affects  the  steam  or  water 
distribution. 

Pipe  i/>  inch  or  less  in  diameter  may  be  cut  to  advantage  with 
a  sharp  hack-saw  instead  of  the  wheel  cutter.  The  hack-saw  will 
leave  a  clean  end  similar  to  that  left  by  the  cutting-off  tool,  but 
considerable  care  is  necessary  to  prevent  the  pipe  from  ruining 


OF  THE 

UNIVERSITY 

OF          > 

RJjii^ 

STEAM  AND  WATER  PIPE-FITTING  311 

the  saw.  There  is  no  danger  until  after  the  teeth  cut  through  the 
wall  of  the  pipe;  then,  while  the  saw  is  moving  over  the  cut- 
through  portion  on  one  side  of  the  cut,  the  saw  is  moving  toward 
a  sharp  wedge-shaped  section  of  pipe  on  the  far  side  of  the  cut, 
and  when  this  sharp  edge  draws  down  past  the  point  of  a  saw- 
tooth, and  takes  the  tooth  on  the  square  front  face,  pressure 
exerted  to  push  the  saw  ahead  can  have  only  one  result,  namely : 
the  tooth  against  which  the  pipe  bears  will  be  lifted  right  up  and 
split  off  the  hacksaw.  Continual  repeating  of  this  action  will 
break  off  so  many  of  the  teeth  that  the  saw  will  become  utterly 
useless. 

USE  OF  THE  HACK-SAW. 

It  is  necessary,  then,  when  cutting  off  pipe  with  a  hack-saw,  to 
cut  around  the  outside  of  the  pipe  instead  of  cutting  squarely 
through  it.  To  do  this,  as  soon  as  the  saw  cuts  through  the  first 
wall,  lower  the  hand  so  that  the  saw  cuts  new  material,  then 
guides  into  the  cut  already  made,  but  does  not  get  a  chance  to 
hit  against  the  sharp  wedge  of  the  opposite  side  of  the  pipe. 
Continue  to  lower  the  hand,  or  to  rotate  the  pipe,  and  it  will  soon 
be  cut  entirely  in  two,  and  not  a  tooth  will  be  broken  out  of 
the  saw. 

The  thinner  the  pipe  the  worse  it  is  in  regard  to  breaking 
the  saw.  Thus  small  pipe  is  much  worse  than  large  pipe,  and  thin 
brass  tubing  is  worse  than  iron  pipe.  A  brass  tube  1  inch  or  so 
in  diameter,  with  the  walls  1/32  inch  thick,  will  break  nearly  all  the 
teeth  out  of  a  new  sawblade  if  the  attempt  be  made  to  saw  square 
through  the  tube. 

THREADING  PIPE. 

Pipe  threading  by  hand  tools  when  the  pipe  is  more  than  2 
inches  in  diameter  is  not  a  job  to  be  envied,  and  some  way  of 
doing  the  work  by  power  should  be  arranged,  no  matter  if  the 
hand  die  must  be  used  for  that  purpose.  Hand  die-stocks  rigged 
for  two  or  more  men,  with  four  to  six  handles,  are  in  use,  but  their 
use  should  never  be  encouraged.  It  is  better,  if  hand  power 
must  be  used,  to  obtain  a  hand-driven  machine,  which  will  enable 
a  man  to  do  the  work  with  some  degree  of  comfort  by  simply 
turning  a  crank.  Again,  when  large  pipe  must  be  cut  off,  the 


312  MILLWRIGHTING 

same  machine  will  do  it  with  a  cutting-off  tool,  thereby  obviating 
the  necessity  for  the  use  of  the  squash-cutting,  pipe-closing  wheel 
cutters. 

When  a  screw-cutting  lathe  is  at  hand,  pipe  may  be  threaded 
in  that  machine,  and  very  long' pipes  may  be  threaded  by  placing 
a  pipe  center  on  a  convenient  post  or  a  neighboring  apple  tree, 
removing  the  tailstock,  and  with  the  near  end  of  the  pipe  held 
in  the  steady-rest  and  internally  driven,  cut  the  thread  with  a 
thread  tool  in  the  usual  way.  Pipe  20  feet  long  may  be  threaded 
in  this  manner  in  a  lathe  48  inches  long  with  swing  enough  to  let 
the  pipe  pass  over  the  saddle. 

Small  and  medium-sized  pipes  may  be  cut  off  and  threaded  by 
means  of  an  ordinary  drilling  machine.  If  the  machine  is  a  verti- 
cal one  with  a  hole  through  the  face-plate,  so  much  the  better. 
Just  dig  a  pit  deep  enough  to  accommodate  the  length  of  the  pipe 
which  is  brought  up  through  the  hole  in  the  face-plate  and 
clamped  fast.  Fasten  the  pipe  die  to  a  chuck  on  the  end  of  the 
drill-spindle,  and  go  ahead  with  the  threading.  The  worst  of  this 
arrangement  is  that  there  is  no  reverse  motion  for  running  the 
die  off  the  pipe  after  the  thread  has  been  cut,  and  it  must  be 
backed  off  by  hand. 

By  chucking-  the  die  on  the  face-plate  of  a  lathe  and  arrang- 
ing a  pipe-vise  on  the  slide-rest,  an  arrangement  is  secured  which 
will  enable  a  man  to  cut  pipe  in  record  time  without  the  necessity 
for  converting  himself  into  a  windlass  or  a  turntable  during  a 
wrestling  bout  with  a  large  and  heavy  die-plate. 

KEEP  THE  TOOLS  SHARP. 

A  good  pipe  thread  cannot  be  made  with  a  dull  tool,  either  in 
a  die-plate  or  in  a  machine.  Tools  for  thread  cutting  are  now 
made  so  they  may  be  sharpened  readily,  therefore  do  not  use 
obsolete  tools  which  cannot  be  readily  sharpened  when  dull.  It 
is  impossible  to  make  a  good  thread  with  a  dull  tool.  It  is  impos- 
sible to  make  a  good  job  at  pipe-fitting  when  the  threads  are  not 
good,  hence  it  is  useless  to  try  to  work  with  dull  thread  tools. 

Avoid,  by  all  means,  a  die  which  cuts  the  thread  too  small, 
and  avoid  a  fitting  which  is  too  large.  It  is  not  possible  to 
make  up  a  first-class  joint  when  the  thread  screws  in  all  over  and 
the  fitting  comes  bang  up  against  a  shoulder,  or  screws  right  over 


STEAM  AND  WATER  PIPE-FITTING  313 

the  uncut  pipe.  Don't  try  to  do  a  good  job  in  this  manner,  for 
you  can't.  Many  a  joint  has  been  "saved"  when  the  pipe  was 
threaded  too  small,  by  making  up  the  joint  with  a  bit  of  fine 
wire-cloth  daubed  in  litharge  and  wrapped  around  the  pipe  before 
the  fitting  was  screwed  on.  Sometimes  the  matter  is  varied  by 
putting  the  wire-cloth  inside  the  fitting,  but  the  effect  is  the  same 
— a  first-class  job  will  never  be  obtained  in  that  manner. 

DEFECTIVE  PIPE  AND  FITTINGS. 

In  spite  of  the  advertised  statement  that  all  pipe  has  been 
proven  to  a  given  pressure,  say  300  to  500  pounds  to  the  inch, 
there  will  always  be  found  pieces  of  split  pipe,  blow-holes,  defec- 
tive fittings  and  other  causes  of  leakage  in  a  pipe  line,  no  matter 
how  carefully  it  may  have  been  put  up.  Therefore,  it  is  necessary 
to  test  each  pipe  system  as  soon  as  possible  after  it  is  in  place. 
The  testing  must  be  done  by  internal  pressure,  either  of  steam, 
water  or  air.  Either  may  be  used  according  to  the  possibility  of 
obtaining  them,  and  the  surroundings.  Water  pressure  is  prefer- 
able if  it  can  be  obtained  easily,  because  leaks  advertise  themselves 
readily  and  are  more  easily  located  with  water  than  when  steam  or 
air  is  used. 

The  plumbers  use  smoke  for  testing  the  pipes  they  erect,  and 
the  gas-fitters  pump  up  an  air  pressure  in  the  system  of  piping 
which  is  closed  at  all  the  outlets,  and  the  inspection  law  requires 
that  a  certain  pressure  be  maintained  for  a  given  time  with  only  a 
stated  drop.  When  this  test  is  withstood  by  the  system  of  pip- 
ing, the  job  is  passed  by  the  inspector. 

Defects  in  pipe  and  fittings,  as  found  after  erection,  are  usually 
in  the  form  of  split  seams,  bad  threads,  over-size  fittings  and 
blow-holes  in  the  latter.  Close  inspection  at  the  time  of  cutting 
and  erecting  the  pipe  is  the  best  safeguard  against  these  aggra- 
vating leaks,  and  when  they  are  discovered  in  a  finished  job,  there 
is  nothing  for  the  millwright  to  do  but  to  take  out  the  defective 
pieces  or  parts  and  replace  them  with  new  ones. 

FINDING  OBSCURE  LEAKS. 

It  is  probable  that  the  only  test  the  millwright  can  give  to  a 
steam  line  will  be  to  turn  on  boiler  pressure  and  then — hunt  for 
leaky  spots.  Fortunately,  steam  condenses  in  pipes  and  usually 


314  MILLWRIGHTING 

the  first  intimation  of  a  leak  is  a  puddle  of  water  which  has 
dripped  from  the  leak.  But  it  sometimes  happens  that  a  leak  will 
not  put  forth  any  water,  particularly  when  the  leak  is  on  the  top 
side  of  a  horizontal  pipe.  Sometimes  there  are  small  leaks  of 
this  character,  which  may  be  heard,  yet  cannot  be  located,  try 
as  hard  as  one  may. 

When  this  is  the  case,  mix  up  a  bucket  of  strong  soap-suds, 
using  some  form  of  soft  soap  if  it  is  to  be  obtained.  A  good 
soap  powder  will  answer.  Common  yellow  soap  may  be  used  if 
necessary,  but  it  is  not  as  good  as  the  others.  When  yellow  soap 
must  be  used,  mix  a  liberal  amount  of  glycerin  with  the  soap  solu- 
tion. With  a  common  paint  brush  go  over  the  pipe,  daubing  the 
fittings  and  along  the  weld  of  the  pipe  where  there  is  any  indica- 
tion that  a  leak  may  exist.  Keep  a  piece  of  white  chalk  with  the 
paint  brush,  and  wherever  a  leak  blows  bubbles  through  the  soap- 
suds, mark  with  the  chalk  for  a  leak. 

DRAINING  PIPE  SYSTEMS. 

A  difference  of  opinion  exists  between  engineers  and  boiler 
users  regarding  the  proper  manner  of  draining  steam  lines.  Some 
persons  claim  that  the  water  of  condensation  should  be  led  back 
to  the  boiler  by  inclining  the  steam  pipe  in  that  direction.  Others 
claim  that  the  flow  of  water  should  always  be  in  the  direction 
taken  by  the  steam.  It  seems  to  the  author  that  the  persons 
claiming  the  best  results  from  a  flow  toward  the  boiler  could 
not  have  thought  the  matter  through  very  carefully,  or  it  would 
have  been  seen  that  with  boilerward  drainage  there  is  always 
danger  of  water  in  the  bottom  of  the  pipe  being  held  up  by  steam 
flow,  even  to  the  extent  of  a  considerable  amount  of  water. 
Then,  when  a  sudden  demand  comes  for  an  increased  flow  of 
steam,  the  water  all  along  the  pipe  is  picked  up  by  the  steam 
rush  and  forced  out  of  the  pipe  to  the  great  discouragement  of 
the  engine  or  other  steam  consuming  device  which  may  be  located 
at  the  far  end  of  the  pipe  line. 

Drain  the  pipes  always  in  the  direction  of  the  flow  of  steam, 
avoid  pockets  and  traps  and  there  will  be  no  trouble  with  rushes 
of  water  into  an  engine  or  other  undesirable  receptacle  for 
water  of  condensation.  Separators  should  always  be  used  between 
engines  and  long  pipe  lines,  but  with  the  boilerward  drain  scheme, 


STEAM  AND  WATER  PIPE-FITTING  315 

separators  are  often  overwhelmed  by  the  rush  of  water  and  unable 
to  take  care  of  it,  hence  that  portion  of  water  which  passes  the 
separator  goes  on  to  knock  out  cylinder  heads  and  double  up  .con- 
necting rods. 

"CUTTING"  OF  VALVES  AND  FITTINGS. 

Valves  are  often  cut  to  pieces  so  badly  that  regrinding  is 
impossible.  Diaphragms,  particularly  those  containing  a  hole  for 
throttling  steam,  are  frequently  cut  out  to  the  almost  full  area 
of  the  steam  pipe  to  which  they  are  connected.  In  cases  like 
these,  we  hear  talk  about  the  "cutting  action  of  steam,"  but  the 
representation  is  a  mistaken  one.  The  author  has  never  found 
a  case  of  cutting  which  could  be  traced  to  steam.  Every  case 
which  has  been  investigated  has  been  found  to  be  due  to  matter 
contained  in  the  steam,  and  particularly  to  the  matter  carried 
along  by  the  water  which  accompanied  the  steam. 

In  certain  cases,  solid  matter  in  small  particles  may  be  carried 
along  with  the  steam  and  the  cut  fittings,  particularly,  valve  discs 
and  seats.  Every  case  of  this  kind  may  be  likened  to  passing  a 
sand-blast  through  the  valve.  In  that  case,  no  man  would  accuse 
the  steam  of  cutting  anything.  It  is  the  action  of  the  sand  or  other 
abrasive  material  which  the  steam  carries  along ;  therefore,  in  all 
valve  or  other  cutting,  it  must  be  laid  to  the  foreign  particles 
which  are  carried  along  by  the  steam  and  probably  in  the  entrained 
water.  When  superheated  steam  is  used,  there  never  has  been 
any  cutting  as  far  as  the  author's  experience  has  demonstrated. 

PIPE  TONGS  AND  THEIR  USE. 

All  too  often  the  condition  of  pipe  tongs  is  a  disgrace  to  the 
man  who  owns  or  uses  them — sometimes  to  both.  Battered  tools 
with  the  lips  cracked,  split  or  battered,  will  never  do  a  good  or  a 
profitable  job  of  piping.  Pipes  are  frequently  split,  crushed  or 
have  sections  sheared  off  by  the  use  of  defective  pipe  tongs.  Many 
leaky  joints  are  defective  on  account  of  the  condition  of  the  tongs, 
which  prevented  the  joint  from  being  properly  set  up. 

Never  try  to  work  with  dull  or  split  pipe  tongs.  If  the  old 
style  tool  is  used,  with  a  single  sharp  corner  to  engage  the  pipe, 
keep  that  corner  very  clean  and  very  sharp,  and  at  just  the  right 
angle  to  properly  engage  the  pipe.  If  the  point  is  too  taper,  it 


316  MILLWRIGHTING 

will  act  as  a  chisel  and  cut  a  hole  in  the  pipe,  probably  cutting 
through  the  weld.  If,  on  the  other  hand,  the  angle  is  too  great, 
the  point  will  not  hold  against  the  pipe,  and  the  tongs  will  either 
slip  or  the  pipe  will  be  flatted  by  the  great  pressure  exerted  in 
attempting  to  turn  the  pipe  around.  The  well  proportioned,  well 
sharpened  pipe  tong  engages  the  wall  of  the  pipe  in  a  tangential 
direction,  and  forces  the  pipe  against  the  back  of  the  tong  where 
the  friction  of  the  tong  against  the  pipe  does  a  good  deal  of  the 
pipe  rotation. 

The  Stilson  pipe  wrench,  which  gives  several  teeth  a  bearing 
against  the  side  of  the  pipe,  is  the  usual  tool  employed  nowadays, 
and  the  action  of  this  tool  is  much  easier  upon  the  pipe  than  the 
old-fashioned  single-lip  tong.  But  the  jaws  must  be  kept  in  good 
shape,  otherwise  the  same  loss  of  time  is  the  penalty. 

For  large  pipes,  the  chain  tongs  hold  their  grip  equally  well  on 
the  pipes  and  on  the  confidence  of  the  user.  The  grip  of  the  chain 
nearly  all  around  the  pipe  forms  a  support  against  the  action  of 
the  sharp  lips  of  the  rolling  lever,  and  it  is  very  seldom  that  a  pipe 
is  cracked  or  split  or  is  flatted  by  the  use  of  chain  tongs. 

THE  ABUSE  OF  PIPE  TOOLS. 

Abuse  occurs  when  the  attempt  is  made  to  work  a  pipe  with 
tools  too  small  or  too  weak  for  the  pipe  to  be  handled.  Screw- 
ing up  a  2-inch  pipe  with  an  18-inch  Stilson  wrench  is  an  example 
of  abuse,  and  the  putting  of  a  piece  of  pipe  on  the  handle  of  that 
18-inch  wrench,  in  order  to  make  up  a  joint  in  the  2-inch  pipe,  is 
an  example  of  stupidity  as  well  as  of  abuse.  Other  examples 
could  be  enumerated  in  abundance,  but  these  are  sufficient.  The 
millwright  has  no  use  for  them.  No  good  mechanic  ever  does 
these  things. 

AIR  AND  WATER  TRAPS. 

When  running  pipe  lines  for  steam,  the  great  thing  to  be 
avoided  is  the  forming  of  pockets  in  which  water  may  collect 
and  thus  cut  down  the  capacity  of  the  pipe.  Under  certain  con- 
ditions, the  pipe  may  become  completely  filled  with  water  in 
spots  and  the  flow  of  steam  cut  off  until  a  lowering  of  pressure 
at  the  discharge  end  is  sufficient  to  overcome  the  hydrostatic 
pressure  of  the  collected  water  and  that  substance  is  driven  out 
of  the  pipe.  Water  traps  or  "pockets"  in  a  steam  pipe  are  always 


STEAM  AND  WATER  PIPE-FITTING  317 

to  be  avoided.  They  are  very  undesirable,  and  in  some  instances 
they  become  dangerous. 

Water  pipes  are  also  cut  down  in  capacity  by  pockets  which 
may  contain  air.  But  in  this  case,  instead  of  a  low  place  in  the 
pipe  giving  trouble,  the  high  spots  are  to  be  avoided.  A  collec- 
tion of  air  in  the  bend  of  a  pipe  passing  over  a  high  place  in  the 
line  may,  in  many  instances,  cut  down  the  pressure  greatly,  and 
in  some  cases  entirely  stop  the  flow  of  water.  Particularly  is  this 
the  case  when  the  pipe  acts  as  a  syphon;  the  pressure  or  weight 
of  the  water  in  the  discharge  leg  must  overcome  the  weight  of 
water  in  the  supply  leg  of  the  syphon. 

In  water  pipes  under  pressure,  the  action  is  the  same,  though 
the  force  not  being  limited  to  14.7  pounds  to  the  square  inch  can 
overcome  to  better  advantage  the  presence  of  air  in  the  pipe. 
In  either  case,  the  loss  of  pressure  amounts  to  the  loss  of  head 
equal  to  the  hight  of  column  of  air  in  the  pipe,  calculated  for  an 
equal  hight  of  water.  Thus,  pockets  and  traps  must  be  avoided 
in  both  steam  and  water  piping,  and  the  straighter  the  pipes 
can  be  run,  in  a  vertical  direction,  the  better  will  the  pipe  line 
serve  its  purpose. 

DEAD-ENDS  AND  DRIPS. 

Dead-ends  in  pipe  lines  should  always  be  avoided  if  possible. 
No  matter  where  placed,  a  dead-end  always  fills  with  water.  If 
the  pipe  be  a  large  one  and  the  dead-end  projects  vertically 
upward,  the  Avater  may  run  out  as  fast  as  it  collects,  but  unless 
a  dead-end  is  drained  in  some  way,  it  will  surely  fill  with  water — 
and  stay  filled.  The  manner  of  its  filling  is  through  the  condensa- 
tion of  the  steam  which  flows  to  the  dead-end.  A  pipe  with  a  close 
end  is  much  like  an  extended  bellows.  The  condensing  of  the 
steam  in  the  pipe  is  like  the  closing  of  the  bellows.  As  every- 
thing— boards  and  leather — is  drawn  down  upon  the  bottom 
board  of  the  bellows,  so  every  bit  of  condensed  water  is  drawn 
to  the  dead-end  of  a  steam  pipe  by  the  condensing  of  the  steam 
in  that  portion  of  the  pipe. 

When  it  is  required  to  maintain  a  circulation  in  a  dead-end, 
a  drip  should  be  provided  which  will  take  care  of  the  water  of 
condensation  as  fast  as  it  collects.  Either  a  drip  must  be  estab- 
lished or  a  loop  must  be  made,  whereby  what  would  be  the  dead- 


318  MILLWRIGHTING 

end  is  connected  into  some  portion  of  the  steam  system  by 
means  of  which  the  water  of  condensation  may  pass  away.  When 
drips  are  used,  they  must  either  be  operated  by  hand,  or  else 
fitted  with  traps  to  prevent  a  loss  of  steam.  Hand-operated  drips 
are  wasteful  of  steam  at  best,  and  it  pays  to  discharge  all  drips 
through  a  trap.  When  there  are  several  drips,  they  may  be 
made  to  work  through  a  single  trap  by  means  of  a  receiver  into 
which  all  the  drips  discharge,  the  trap  taking  care  of  the  con- 
tents of  the  receiver. 

Under  certain  conditions,  the  trap  may  be  made  to  do  duty 
as  a  receiver,  but  it  is  usually  better  to  have  an  independent  ves- 
sel for  that  purpose.  In  many  instances,  in  running  several  drips 
into  the  same  discharge,  it  is  necessary  to  place  a  check  value  in 
each  drip  pipe  in  order  that  water  may  not  be  blown  back  into 
any  pipe  when  that  one  is  not  in  use  and  one  or  more  of  the 
others  are  under  pressure.  Sometimes  it  has  been  found  bene- 
ficial to  place  a  plug  valve  in  each  drip,  adjacent  to  the  check 
valve,  in  order  that  the  discharge  may  be  made  more  uniform 
under  certain  conditions. 

In  hand-operated  drips,  a  most  wasteful  tendency  or  inclination 
is  observed  to  let  steam  blow  through  when  it  is  desired  to  heat 
things  a  little  hotter  than  usual.  This  applies  to  steam  radiators 
particularly.  When  there  is  a  bit  of  cold  weather,  and  a  little 
more  heat  is  needed,  it  is  the  custom  of  most  people  to  open  the 
drip  valve  and  blow  steam  through  the  radiator  until  the  vapor 
escapes  into  the  atmosphere  in  clouds.  This  is  a  mistaken  idea. 
All  the  steam  that  can  be  forced  through  a  radiator  will  not 
warm  the  room  any.  It  is  the  steam  which  is  condensed  in  the 
radiator  which  does  the  heating.  A  pound  of  steam  under  10 
pounds  gage  pressure  will,  when  cooled  in  a  radiator  down  to  212 
degrees,  give  up  only  23  heat  units.  But  when  the  same  pound 
of  steam  is  condensed  in  the  radiator,  it  gives  up  966  heat  units ; 
showing  the  very  little  benefit  derived  from  blowing  live  steam 
through  a  radiator,  and  the  great  heating  power  of  steam  which 
is  condensed  in  the  radiator. 

THE  STEAM  LOOP. 

There  is  a  method  of  returning  water  to  the  boiler  which  is 
known  as  the  "steam  loop."  This  device,  or  rather  this  arrange- 


STEAM  AND  WATER  PIPE-FITTING 


319 


ment,  is  merely  a  dead-end  of  piping,  so  arranged  that  when  full 
of  water  the  liquid  will  run  out  by  gravity,  leaving  the  dead-end 
full  of  steam  to  repeat  the  operation  of  filling  with  water  and  auto- 
matically emptying  itself.  The  operation  of  the  steam  loop  may 
be  understood  by  reference  to  Fig.  121,  in  which  the  steam  loop 
is  shown  in  connection  with  a  steam  boiler.  A  check  valve,  a, 
is  placed  in  the  pipe  which  enters  the  boiler  at  any  convenient 
point,  either  in  the  steam  room  or  below 
the  water  line.  The  pipe  d  connected 
with  the  system  it  is  required  to  drain, 
acts  as  a  dead-end,  the  check  valve  clos- 
ing the  lower  end  of  the  pipe,  and 
closing  it  against  the  entrance  of  steam 
from  the  boiler  side. 

Any  steam  which  may  be  present  in 
pipe  d  is  condensed  and  runs  down 
upon  the  valve,  filling  the  pipe  to  some 
point  in  the  neighborhood  of  b,  or  so 
high  that  the  weight  of  water  on  the 
check  valve  a  forces  open  that  device, 
whereupon  the  water  in  pipe  b  flows 
by  its  own  weight  into  the  boiler.  Or, 
a  portion  of  the  water  flows  in,  until 
the  weight  of  water  in  the  pipe  is  un- 
able to  hold  the  check  valve  open.  Then 
the  valve  closes  and  remains  closed  un- 
til enough  water  to  open  the  valve  again 
collects  in  pipe  b.  If  found  necessary, 

the  pipe  b  may  be  enlarged  to  contain  a  considerable  quantity 
of  water  as  indicated  by  the  dotted  lines  c,  which  represent  a 
large  pipe  or  cylinder  of  any  required  capacity.  As  the  steam 
pressure  is  nearly  the  same  both  below  and  above  check  valve  a, 
the  opening  and  closing  of  that  valve  will  depend  entirely — or 
nearly  so — upon  the  weight  of  the  valve  check  and  the  hight  of 
the  column  of  water  which  collects  in  pipe  b. 

MAKING  UP  FLANGE  CONNECTIONS. 

In  making  up  flanged  joints,  take  care  to  have  all  union  sur- 
faces clean  and  free  from  metal  chips,  sand,  or  bits  of  string. 


Boiler 


FIG.    121.— THE    STEAM 
LOOP. 


320 


MILLWRIGHTING 


Any  or  all  of  these  will  cause  a  bad  fit  of  the  gasket  and  offer  a 
path  for  the  escape  of  steam  or  water  under  pressure.  When 
tightening  the  bolts  between  a  pair  of  flanges,  make  sure  that 
the  flanges  are  brought  to  an  easy  bearing,  just  touching  the 
gasket,  and  that  all  the  nuts  are  screwed  easily  down  until  they 
all  bear  evenly — screwed  up  by  the  fingers  is  tight  enough— ibefore 
any  strain  is  put  upon  any  nut.  Then  screw  up  each  nut  a  quar- 
ter of  a  turn,  passing  from  one  to  the  other  until  all  the  nuts 
have  had  a  quarter  of  a  turn.  Then  go  over  them  all,  again  and 
again,  a  quarter  of  a  turn  at  a  time,  until  the  joint  is  tight  and 
the  bolts  all  have  an  equal  strain  upon  them. 

Above  all  things,  avoid  screwing  up  one  nut  tight  and  leaving 
another  one  loose.  When  the  flanges  are  exactly  the  same  distance 
apart  all  around  the  pipe,  then  it  is  pretty  certain  that  the  bolts 
are  all  bearing  evenly  and  the  joint  will  not  leak. 

EXPANSION  OF  STEAM  PIPES. 

The  coefficient  of  expansion  of  iron  is  given  by  Howard,  engi- 
neer in  charge  of  the  U.  S.  Testing  Machine  at  Wratertown 
Arsenal,  as  0.0000067302  inch  per  inch  for  each  degree  of  tem- 
perature Fahr.  Then,  a  pipe  heated  300  degrees,  and  100  feet 


Boiler 


FIG.    122.— BADLY    ARRANGED    PIPE    CONNECTIONS. 

long,  would  have  an  elongation  of  0.0000067302X100X300X12— 
2.322872,  or  about  2  1/3  inches.  In  pipe  fitting,  about  this 
amount  of  elongation  must  be  taken  care  of.  Sometimes  it  is 
necessary  to  use  expansion  joints  where  sliding  surfaces  are 


STEAM  AND  WATER  PIPE-FITTING 


321 


arranged,  but,  if  possible,  it  is  preferable  to  use  one  or  two 
angles  in  the  pipe  and  let  the  lever  arms  thus  secured  take  up  the 
elongation  by  swinging  sidewise. 

In  connecting  boilers,  for  instance,  there  is  nearly  always 
trouble  when  they  are  joined  as  in  Fig.  122,  the  main  pipe  extend- 
ing straight  across  from  one  boiler  to  the  other,  and  the  expansion 
of  the  pipe  serving  to  spread  the  boilers  apart  and  to  break  the 
connections  between  them  and  the  pipe.  A  properly  arranged 


Boiler 


Boiler 


FIG.   123.— BOILERS   PROPERLY  PIPED. 

steam  connection  is  shown  by  Fig.  123,  the  expansion  in  pipe  a 
being  taken  up  by  the  lever  arms  connecting  pipe  a  with  the  boiler, 
and  the  expansion  being  felt  at  b  and  at  c  by  merely  a  slight  twist- 
ing movement  at  those  points,  which  is  easily  absorbed  either  by 
the  pipe  threads,  or  by  a  movement  around  the  bolts  if  the  con- 
nections are  flanged.  Sometimes  the  swing  is  taken  up  by  a  slight 
bending  of  the  pipes  connecting  a  with  b  and  c. 

PACKING  AND  REGRINDING  VALVES. 

Globe  stop  valves  usually  come  with  a  bit  of  w'cking  in  the 
stuffing  box  around  the  stem.  Never  steam  up  without  first 
repacking  the  stems  with  more  and  well  lubricated  packing,  either 
wicking  or  some  specially  prepared  material.  Soapstone  or  plum- 
bago should  be  used,  with  a  little  cylinder  oil,  in  the  stem-packing 
of  steam  valves.  The  author  makes  it  an  invariable  rule  never 


322  MILLWRIGHTING 

to  quit  a  steam  line  until  each  and  every  valve  has  been  stem- 
packed  and  the  bonnet  removed  after  steam  has  been  blown 
through  the  pipe  under  full  boiler  pressure  with  the  far  end  of  the 
pipe  wide  open. 

This  drives  out  thread-chips  and  other  dirt  which  may  be  in 
the  pipe ;  then,  upon  removing  the  bonnets  before  closing  any  of 
the  valves  in  the  line,  there  is  a  chance  to  remove  any  large  frag- 
ments of  metal  which  may  have  lodged  across  the  seats.  A  good 
deal  of  trash  is  sometimes  found  in  the  globes  of  valves  in  this 
manner,  trash  which  would  seriously  injure  the  valves  had  they 
been  closed  without  first  removing  the  bonnets,  as  described  above. 

Every  pipe  system  should  be  provided  with  a  good  valve 
regrinding  layout,  and  as  soon  as  a  valve  leaks,  remove  the  bonnet, 
true  up  the  seat  and  disk — or  put  in  a  new  disk — and  that  valve  is 
good  for  years  of  use  if  thus  decently  treated  and  taken  care  of. 
The  millwright  can  make  a  set  of  valve  files  for  use  with  the  breast 
drill  or  bit-brace,  but  it  is  time  and  money  saved  to  purchase  one 
of  the  many  good  sets  of  valve  regrinding  tools  now  in  the  market. 
And  when  purchased,  use  them  frequently.  Never  wait  until  a 
valve  leaks  badly  before  regrinding.  "Regrind  as  soon  as  found 
leaky"  is  the  watchword  for  valves. 

And  one  word  more — repack  a  valve  the  instant  it  will  not 
screw  down  tight  enough  to  stop  steam  coming  out  around  the 
stem.  Leaky  valve  stems  are  always  an  indication  of  a  lazy,  slip- 
shod management. 

MAKING  UP  PIPE  JOINTS. 

For  making  up  permanent  screw  joints  in  pipe,  where  it  is 
not  necessary  to  break  the  joints  again,  nothing  is  better  than  good 
red  lead,  though  litharge  (yellow  oxide  of  lead)  answers  nearly 
as  well.  For  screw  joints  which  may  have  to  be  taken  down  fre- 
quently, plumbago  mixed  with  cylinder  oil,  makes  a  good  material 
for  daubing  either  threads  or  flanges  ;  it  is  also  good  on  flange  bolt 
threads.  For  threaded  pipe,  use  as  thick  as  possible.  A  mixture 
which  will  run  is  too  thin.  It  daubs  things  too  much.  For  flange 
use,  it  may  be  mixed  thin  enough  to  allow  of  being  spread  on  the 
surfaces  with  a  brush.  When  nice  work  is  required,  daub  the 
inside  of  fittings,  valves,  etc.,  and  it  will  not  show  as  when  daubed 
on  pipe,  nipples,  etc. 


STEAM  AND  WATER  PIPE-FITTING  323 

CUTTING  GASKETS  AND  PACKING. 

When  a  washer  cutter  is  at  hand,  soft  gaskets  may  be  cut  to 
measure  in  advance,  but  for  irregular  work,  and  when  circular 
gaskets  are  not  on  hand  ready  made,  there  is  no  better  way  of 
cutting  them  than  with  a  round-face  or  ball-pene  hammer  in  the 
good  old  way,  hammering  the  sheet  of  packing  lightly  over  the 
edges  of  the  ilange,  taking  care  not  to  hit  with  a  corner  of  the 
hammer,  or  to  strike  hard  enough  to  mar  the  edge  of  the  iron  sur- 
face. Hammer  around  the  edge  of  a  bolt-hole  first,  then  slip  a 
peg  into  the  hole,  and  hammer  around  another  bolt-  or  stud-hole. 
Another  peg  in  the  last  hole  and  the  packing  and  casting  are  held 
firmly  together,  allowing  the  rest  of  the  cutting  to  be  hammered 
off  with  little  trouble  in  holding  the  packing  in  place  during  the 
operation. 

If  it  is  desired  that  the  gasket  should  come  off  whole,  when  the 
joint  is  broken,  then  dress  it  with  plumbago  before  making  up 
the  joint.  If  a  permanent  joint  is  desired,  use  red  lead  or  lith- 
arge in  making  up  the  joint.  If  there  is  trouble  in  holding  the 
packing  in  place,  treat  it  with  litharge  and  glycerin,  let  the  steam 
pressure  come  upon  the  joint  gradually,  tighten  up  well  and  after 
pressure  is  on,  and  that  gasket  will  never  come  off  unless  it  is 
chipped  off  with  a  chisel.  Litharge  and  glycerin  make  an  excel- 
lent cement  for  stopping  cracks  in  iron;  it  is  steam  and  acid 
proof,  and  stays  right  where  it  is  put. 


CHAPTER  XVII. 

ERECTING    STEAM    ENGINES. 

The  setting  of  a  steam  engine  should  commence  with  the  build- 
ing of  its  foundation;  and  even  before  that — with  the  design  of 
the  foundation,  which  should  be  broad  enough  at  the  bottom, 
where  it  bears  upon  the  soil,  that  no  tremble  or  shake  will  ever 
cause  the  foundation  to  settle  in  whole  or  in  part.  The  office  of 
an  engine  foundation  is  threefold,  or  it  must  fill  three  require- 
ments, either  fully  or  partially,  according  to  the  surroundings. 
Briefly  stated,  these  three  functions  of  the  engine  foundation  are : 

I. — To  support  the  mass  of  the  engine  at  a  given  hight 

or  level. 

II. — To  preserve  alinement  of  engine  with  the  main  shaft. 
III. — To  absorb  vibrations  of  the  moving  parts  of  the  engine. 

A  few  timbers  thrown  upon  the  earth  would  hold  the  engine 
as  far  as  the  first  requirement  is  concerned,  but  might  not  fill 
the  others.  But  in  connection  with  the  second  requirement,  the 
foundation  must  be  so  well  distributed,  according  to  the  nature  of 
the  earth  underneath  it,  that  there  can  never  be  any  possibility  of 
settling.  The  load  to  the  square  foot  must  be  light.  While  build- 
ing foundations  are  frequently  loaded  to  one  ton,  or  even  two  tons 
or  more  in  ordinary  earth,  engine  foundations  seldom  carry  more 
than  1000  pounds  to  the  square  foot,  including  the  weight  of  the 
foundation  itself.  The  millwright  is  safe  in  taking  this  load  as  the 
limit  for  engine  foundations. 

FOUNDATIONS  TO  ABSORB  VIBRATION. 

A  balance  wheel  may  be  likened  to  a  rotary  dash-pot  for  the 
purpose  of  absorbing  or  equalizing  the  irregular  forces  which  act 
to  retard  or  accelerate  the  movement  of  the  wheel  upon  its  axis. 
The  foundation  is  to  absorb  in  a  manner  somewhat  similar  the 
vibration  of  the  several  parts  of  the  engine.  Thus  it  is  necessary 
that  the  foundation  be  constructed  in  a  single  mass,  or  so  fastened 

324 


ERECTING  STEAM  ENGINES  325 

together  that  one  portion  cannot  move  independent  of  the  other 
portions.  For  this  reason  it  is  best  to  make  the  foundation  of 
concrete,  in  a  single  block,  or  monolithic.  Thus  a  foundation  com- 
posed of  well  proportioned  concrete  is  preferable  to  any  other 
kind,  although  brick  or  stone  may  be  used  to  advantage  if  these 
materials  are  cheapest. 

SUSPENDED  FOUNDATIONS. 

For  the  purpose  of  absorbing  vibration,  and  incidentally  help- 
ing the  designer  of  the  machinery  to  cover  up  some  inferior  work 
— the  engine  would  not  vibrate  if  all  parts  were  perfectly  designed 
— it  does  not  matter  whether  the  foundation  is  placed  on  the 
ground  or  is  suspended  by  means  of  rods  from  some  overhead 
structure.  In  a  case  of  this  kind,  however,  it  would  be  necessary 
to  reinforce  the  lower  portions  of  the  foundation  so  that  no  part 
of  it  shall  be  in  tension.  There  is  some  tensile  strength  to  con- 
crete, but  good  engineering — and  good  millwrighting — requires 
that  the  tensile  strength  be  neglected  in  every  instance,  and  that 
steel  sections  be  put  in,  capable  of  carrying  every  particle  of  the 
tensile  stress  with  a  good  factor  of  safety.  This  holds  good  in  all 
concrete,  whether  for  a  foundation,  a  floor,  a  beam  or  a  wall. 

ALWAYS  USE  A  TEMPLET. 

Never  attempt  to  build  a  foundation  for  an  engine,  or  for  any 
other  machine  which  requires  anchor  bolts,  without  first  construc- 
ting a  templet,  in  which  the  location  of  the  bolt-holes  are  an 
exact  duplicate  of  the  holes  in  the  engine  frame.  The  center  line 
and  the  shaft  line  shall  both  be  marked  upon  the  templet  in  their 
exact  positions  in  relation  to  the  bolt-holes  which  they  occupy  in 
the  engine.  The  templet  is  usually  made  of  %-inch  boards  fast- 
ened together  with  clinch  nails  or  screws,  though  it  would  be  a 
profitable  arrangement  for  engine  builders  to  keep  in  stock  some 
knock-down  templets  made  of  light  steel  angles  and  channels,  these 
templets  being  sent  out  with  the  engine,  or  in  advance,  and  re- 
turned to  the  engine  builder  after  having  been  used. 

SETTING  ANCHOR  BOLTS  WITH  THE  TRANSIT. 
Anchor  bolts  for  engines  and  other  machines  are  frequently 
set  with  the  transit  for  the  purpose  of  dispensing  with  the  templet. 


326 


MILLWRIGHT1NG 


Where  there  are  only  one  or  two  bolts,  this  method  answers  very 
well,  but  when  there  are  numerous  bolts,  as  in  ease  of  an  engine, 
the  possibility  of  error  is  in  proportion  to  the  number  of  bolts,  and 
this  proportion  is  considerably  increased  by  the  possibility  of  some 
of  the  bolts  being  pushed  out  of  place  during  the  construction  of 
the  concrete.  By  the  templet  method,  the  bolts  being  suspended 
from  the  templet,  there  is  little  danger  of  one  or  two  bolts  being 
disarranged.  If  one  bolt  goes,  all  must  go. 

CONSTRUCTING  A  TEMPLET. 

Fig.  124  represents  a  templet  layout  as  arranged  for  an  engine 
of  the  detached  outboard  bearing  type.  First  draw  the  center  line 
a  b,  sketch  A,  on  a  rloor  or  smooth  platform  large  enough  for 


h          fc 


FIG.    124.— LAYING   OUT  AND   CONSTRUCTING  A   TEMPLET. 

the  laying  out  of  the  foundation  full  size.  Next  draw  the  shaft 
line  b  c,  taking  care  to  make  this  line  exactly  at  right  angles,  or 
perpendicular  to  the  line  a  b.  The  millwright  will  "square"  one 
line  with  the  other.  The  radius-board,  chapter  V,  page  51,  is 


ERECTING  STEAM  ENGINES  327 

the  proper  appliance  for  use  in  squaring  these  lines  with  each 
other.  Next  lay  off  the  distance  b  d,  equal  to  the  space  between 
shaft  line  and  anchor  bolt  holes  under  front  end  of  cylinder.  Next 
find  the  distance  a  d,  and  lay  that  down,  locating  the  holes  in  the 
head  end  of  cylinder.  The  distance  a  f  and  a  g  locate  the  space 
between  the  holes  /  and  g  at  a,  as  well  as  at  d.  Next  locate  the 
holes  at  h  i,  on  line  c,  also  on  line  c,  the  latter  being  for  the  out- 
board pillow-block  anchor  bolts. 

If  there  are  to  be  other  bolts  in  the  foundation,  they  should 
be  located  as  above.  Some  engines  have  an  anchored  arm  or 
bracket  to  carry  the  end  of  the  rock  shaft.  When  such  a  bracket 
is  attached  to  the  foundation,  it  should  be  located  on  the  diagram. 
When  dash-pots  are  used,  they  also  should  be  located,  and  it  is 
well  to  mark  the  diameter  of  the  exhaust  pipe  where  it  drops  below 
the  floor  level  and  a  pocket  or  cavity  must  be  left  for  it  in  the  con- 
crete. These  things  are  not  shown  on  the  diagrams  either  at  A 
or  at  B.  The  millwright  may  mark  or  omit  them  as  he  chooses. 
One  thing  should  always  be  marked,  and  that  is,  the  center  line 
and  faces  of  the  engine  pulley,  as  at  /,  which  indicates  the  center 
line,  while  k  and  /  represent  the  faces  or  sides  of  the  pulley.  These 
lines  are  very  handy  for  locating  the  templet  when  it  is  necessary 
to  bring  the  engine  to  a  pulley  already  located  upon  the  main 
shaft. 

The  diagram  is  now  ready  for  the  templet  which  is  to  be  built 
upon  it.  Procure  some  good  sound  lumber,  white  pine,  spruce  or 
yellow  pine.  Do  not  use  whitewood,  it  warps  too  much.  White 
pine  is  the  best,  but  that  is  probably  out  of  the  question.  Spruce 
will  answer  very  well,  and  yellow  pine  makes  a  fine  templet  but  a 
very  heavy  one,  as  green  yellow  pine  boards  1-inch  thick  weigh 
five  pounds  to  the  square  foot.  Use  dry  lumber.  If  necessary, 
dry  it  before  making  the  templet,  for  if  green  the  templet  will  not 
remain  accurate.  Hemlock  may  be  used  but  it  is  not  very  desir- 
able lumber. 

Have  the  boards  planed  on  four  sides  if  possible,  on  one  side 
and  one  edge,  anyway.  It  is  possible  to  make  a  templet  from 
rough  undressed  boards,  but  it  is  not  a  desirable  thing  to  do  and 
the  accuracy  is  apt  to  suffer  by  so  doing.  Even  with  rough  lum- 
ber, one  edge  of  two  boards  must  be  jointed  straight  and  placed 
one  upon  each  center  line  as  at  m  and  n,  sketch  B,  Fig.  124. 


328  MILLWRIGHTING 

Some  mechanics  construct  templets  with  the  center  line  drawn 
down  the  middle  of  one  of  the  boards,  but  the  author  finds  it 
better  to  take  the  edge  of  a  board  as  the  center  line  whenever 
possible.  This  has  been  done  on  both  the  cylinder  and  shaft 
center  lines,  thus  locating  the  center  lines  in  a  manner  which  can 
not  rub  out  as  sometimes  happens  when  a  line  is  used  down  the 
side  of  a  board. 

Sketch  J>  shows  so  plainly  the  method  of  constructing  the 
templet  that  little  further  direction  is  necessary.  The  brace  o 
must  be  carefully  located  and  fastened  to  make  sure  that  there  is 
no  shifting  of  the  outboard  bearing  bolt-holes.  It  will  be  noted  that 
the  brace  o  bears  against  the  templet  firmly  at  q  and  at  r,  the  brace 
being  carefully  fitted  at  those  points,  then  firmly  clinch-nailed  or 
screwed  as  indicated  in  sketch  B.  The  wheel  location  is  shown 
at  p,  enabling  the  templet  to  be  readily  brought  to  the  necessary 
point,  and  permitting  the  masons  to  see  where  the  wheel  is  located, 
thereby  keeping  the  foundation  free  from  possible  interference 
with  the  lower  side  of  the  wheel. 

SETTING  UP  A  TEMPLET. 

The  templet  may  be  placed  on  ledgers  which  are  supported 
by  posts  like  ordinary  batters,  or  the  ledgers  may  be  suspended 
from  overhead.  The  latter  method  is  far  more  preferable  as  it 
leaves  the  space  around  the  foundation  free  from  all  timbers  or 
posts  which  would  interfere  to  some  extent  with  the  movement 
of  workmen  and  material.  A  templet  suspended  from  above  is 
best.  It  is  good  practise  to  locate  the  under  side  of  the  templet 
upon  the  finish  level  of  the  top  of  the  foundation,  thus  allowing 
measurements  to  be  taken  direct  from  that  surface. 

The  templet  should  be  alined  by  the  transit,  or  if  that  instru- 
ment is  not  available,  the  "plumb-bob  and  sight  line"  method 
may  be  used  as  described  in  chapter  XIV,  page  269.  The  con- 
crete should  be  selected  as  noted  on  page  74,  chapter  VI,  and  it 
should  be  mixed  wet  enough  that  water  will  stand  on  top  of  each 
layer  after  ramming.  As  long  as  the  cement  is  not  washed  away, 
too  much  water  cannot  be  used  in  mixing  or  placing  concrete. 
Never  put  concrete  in  place  while  so  dry  that  water  cannot  be 
brought  to  the  surface  by  tamping. 


ERECTING  STEAM  ENGINES  329 

PLACING  ENGINES  UPON  GREEN  FOUNDATIONS. 

The  forms  may  be  constructed  as  directed  for  foundations, 
in  chapter  VI,  page  60.  The  engine  should  not  be  placed  on 
the  foundation  for  at  least  one  week  after  the  cement  was  ram- 
med. Two  weeks  is  better,  but  one  week  will  answer  if  care 
is  used  in  working  on  the  green  concrete. 

Sometimes  it  is  absolutely  necessary  to  place  a  machine  on  a 
foundation  at  once.  Concrete  may  be  prepared  to  receive  a  load 
in  36  hours  if  absolutely  necessary.  To  do  this,  heat  the  concrete 
mixture  while  dry  by  shoveling  it  over  a  piece  of  sheet  iron  with  a 
fire  underneath.  Heat  the  material  as  hot  as  possible  up  to  the 
boiling  point  of  water,  then  gage  with  boiling  water  and  in  very 
small  quantities,  and  ram  in  olace  immediately,  for  cement  thus 
treated  sets  very  quickly. 

As  fast  as  the  concrete  is  rammed,  surround  it  with  bagging, 
shavings,  sawdust  or  a  similar  substance,  and  keep  the  covering 
wet  with  hot  water.  Steam  may  be  used  for  this  purpose  if 
available.  As  soon  as  the  concrete  has  been  all  rammed  in  place, 
cover  fully  with  heat  retaining  material  as  above  described,  and 
keep  moist  arid  hot  for  18  hours  at  least,  and  24  hours  will  be 
better.  At  the  expiration  of  that  time,  remove  the  form,  or  bet- 
ter yet,  slide  back  each  portion  of  the  form,  leaving  two  or  three 
inches  between  the  foundation  and  the  form.  Cover  outside  of  the 
form  as  before  with  bagging,  boards,  shavings,  or  even  with  earth 
outside  the  boards,  an  dthen  turn  live  steam  into  space  between 
the  displaced  form  and  the  concrete  foundation.  Twenty-four 
hours  of  steam  treatment,  keeping  the  concrete  at  212  degrees 
F.,  and  the  outside  of  the  concrete,  at  least,  hardens  so  it  will 
carry  1500  to  1800  pounds  to  the  square  foot  safely.  The  interior 
of  the  concrete  will  harden  quickly  if  it  be  heated  to  the  degree 
mentioned.  If  the  material  be  heated,  and  the  whole  business 
kept  hot,  the  hardening  temperature  will  probably  be  reached 
entirely  through  the  foundation,  but  if  it  be  rammed  with  cold 
concrete  and  the  attempt  made  to  steam  harden,  it  is  extremely 
likely  that  only  the  outside  of  the  concrete  will  be  hardened  owing 
to  concrete  being  a  very  poor  conductor  of  heat.  This  is  one  of 
the  reasons  why  concrete  is  fireproof.  It  takes  so  long  to  heat  a 
body  of  concrete  that  any  ordinary  fire  is  extinguished  or  has 
burned  out  before  many  inches  of  concrete  have  become  heated 
to  the  point  of  failure. 


330  MILLWRIGHTING 

FOUNDATION  BOLTS  AND  POCKETS. 

When  it  was  the  custom  to  build  brick  or  masonry  engine 
foundations,  it  was  also  the  custom  to  get  out  top  and  bottom 
pocket  stones  with  holes  drilled  through  them  to  accommodate 
the  anchor  bolts.  With  concrete  foundations,  cap  and  pocket 
stones  are  not  necessary,  and  the  anchor  bolts  may  be  built  right 
into  the  foundation,  or  the  bolts  may  be  later  placed  in  holes 
formed  for  their  reception  by  placing  pieces  of  steam  pipe  in  the 
templet  holes  which  were  enlarged  for  this  purpose.  Some  con- 
structors withdraw  the  pipes,  some  leave  them  in  place.  The 
author  prefers  to  withdraw  the  pipes  and  fill  the  spaces  around  the 
pipes  with  neat  cement. 

When  anchor  bolts  are  to  be  inserted  afterwards,  pockets  may 
be  left  through  which  to  adjust  the  nut  and  washer  at  the  lower 
end  of  each  bolt.  All  that  is  necessary  to  form  a  pocket  is  a  piece 
of  board  with  a  hole  bored  to  fit  rod  or  pipe,  and  two  other  pieces, 
tapered  from  one  end  to  the  other,  for  the  sides  of  the  pocket. 
Hang  the  top  board  on  the  bolt  or  pipe,  place  the  taper  side  boards 
under  the  edges  of  the  top  board.  Place  a  brick  or  a  flat  stone 
against  the  inner  end  of  the  three  bits  of  board,  then  fill  between 
them  with  sand  which  should  be  tamped  in  well.  Do  not  nail  the 
pieces  of  board  together.  The  sand  will  prevent  them  from  falling 
down  until  the  concrete  gets  next  to  them,  and  they  could  not  be 
forced  down  after  that. 

WHO  SHALL  FURNISH  ANCHOR  BOLTS?. 

Sometimes  it  is  necessary  to  use  pipes  large  enough  to  permit 
the  passage  of  a  hexagonal  nut  on  the  lower  end  of  an  anchor  bolt. 
In  cases  of  this  kind,  the  anchor  bolts  are  dropped  into  the  pipes 
which  arc  then  filled  with  neat  cement.  The  only  excuse  for  this 
method  of  setting  anchor  bolts  is  that  they  have  not  come  to  hand 
when  the  foundation  is  being  built.  The  lack  of  foundation  bolts 
at  the  time  they  are  wanted  has  led  to  all  sorts  of  methods  of  pro- 
viding the  bolts.  Some  machine  manufacturers  do  not  furnish 
them  at  all.  Other  manufacturers  send  bolts  on  ahead  of  the 
machine  or  engine,  and  still  others  send  the  bolts  with  the  machine. 

The  excuse  made  by  some  concerns  for  not  including  anchor 
bolts  with  their  machines  is  that,  owing  to  local  conditions,  the 
length  of  the  bolt  is  liable  to  be  changed,  and  if  they  have  to  be 


ERECTING  STEAM  ENGINES  331 

cut  and  welded,  the  purchaser  might  as  well  make  his  own  anchor 
bolts  as  to  pay  for  the  bolts  and  then  for  changing  them.  This 
point  is  well  taken,  but  the  real  reason  for  not  furnishing  anchor 
bolts  is  that  the  manufacturer  gets  just  as  much  for  his  machine 
or  engine  without  the  bolts  as  he  does  when  bolts  are  furnished. 
By  applying  the  "something  for  nothing"  principle,  the  manufac- 
turer simply  gets  rid  of  paying  for  the  bolts — quite  a  tidy  saving 
when  hundreds  of  sets  of  bolts  are  figured  up. 

ALINING  THE  ENGINE. 

When  accurate  work  is  required,  as  is  necessary  in  all  large 
engines,  the  cylinder  should  be  alined  to  coincide  with  the  building 
line  before  the  frame  is  fastened  by  the  anchor  bolts.  There  is  no 
better  way  of  alining  an  engine  than  by  stretching  a  string  through 
the  cylinder  after  the  head,  piston,  piston  rod  and  crosshead  have 
been  removed.  Engines  of  considerable  size  are  shipped  with  all 
the  separate  parts  securely  boxed,  to  be  assembled  after  arrival. 
Smaller  engines  are  shipped  completely  or  partially  assembled,  but 
it  is  the  unvarying  custom  of  the  author  to  dismantle  every  engine 
he  is  to  erect,  and  to  find  by  personal  inspection  the  condition  of 
the  hidden  parts  of  the  engine. 

The  engines  of  today  are  the  best  ever  made,  yet,  as  closely 
inspected  during  manufacture  as  all  machinery  parts  are  supposed 
to  be,  there  is  opportunity  for  something  to  be  passed  which  will 
give  trouble  if  not  detected  at  the  very  start.  Hence  the  habit 
of  personal  inspection,  which  has  always  served  the  author  well. 

PERSONAL  EXAMINATION  OF  WOR$  DURING  ERECTION. 

In  one  instance,  when  the  valves  of  a  corliss  engine  were  taken 
out  to  note  the  manner  of  their  fitting,  a  bit  of  loose  core  sand 
was  noticed  in  one  of  the  ports.  Investigation  revealed  the  fact 
that  the  sand-blast  had  evidently  been  forgotten  when  that  engine 
casting  was  cleaned  up,  for  from  the  ports  of  that  engine  was 
taken  four  quarts  of  core  sand!  Imagine  the  manner  in  which  the 
valves  and  piston  of  this  engine  would  have  stood  up  (or  lain 
down)  to  its  work  had  it  been  started  before  the  presence  of  core 
sand  had  been  discovered. 

Look  to  the  fit  of  the  bearings  and  do  not  be  afraid  of  scraping. 
Shop  work  is  sometimes  worked  upon  such  a  high-pressure  system 


332 


MILLWRIGHTING 


that  the  man  in  the  shop  says :  "Oh !  that's  good  enough.  Get  it 
out  of  here.  Let  the  man  who  sets  it  up  do  the  rest  of  the  fitting 
— he  hasn't  got  anything  to  do  anyway  except  to  bolt  the  thing 
together,  and  he  can  fix  that  as  well  as  not."  And  so  it  goes.  The 
shop  man  makes  a  record  in  getting  work  off  his  hands  and  the 
field  man  spends  his  time  writing  letters  to  the  shop  in  the  hopes 
of  having  shop  work  done  in  the  shop. 

The  old  adage  that  "eternal  vigilance  is  the  price  of  liberty" 
may  well  be  adopted. by  the  millwright,  who  furthermore  should 


FIG.    125.— CROSS   FOR  CENTERING  HEAD   END   OF   CYLINDER. 

make  up  his  mind  to  see  personally  every  internal  part  of  each 
machine  he  sets  up.  It  is  only  right  that  the  "ounce  of  prevention" 
examination  should  be  employed  to  prevent  the  "pound  of  cure" 
overhauling  from  being  necessary  after  the  new  machine  has  been 
started  and  has  failed  to  work  satisfactorily. 

A  four-armed  cross  should  be  sent  out  with  the  engine,  which 
will  just  fit  inside  the  counterbore  of  the  head  end  of  the  cylinder. 
If  the  cross  has  been  overlooked,  make  one  as  shown  by  Fig.  125.' 
Two  pieces  of  board,  21/o  or  3  inches  wide,  are  halved  together 
and  screwed  or  clinch-nailed  as  shown ;  then  a  hole,  %  or  1  inch 
in  diameter,  is  bored  through  at  c,  a  bit  of  tin  or  other  thin  metal 


ERECTING  STEAM  ENGINES 


333 


d,  is  tacked  over  the  hole,  and  a  small  hole  e,  just  the  size  of 
the  line  used,  is  pierced  through  the  tin  as  shown.  This  hole  is 
used  as  a  center  from  which  to  strike  the  circle  /  g  g  g,  which  is 
the  exact  diameter  of  the  cylinder  counterbore.  A  mark  is  made 
on  each  end  of  the  wooden  cross  as  at  g,  g,  then  each  arm  is  cut 
off  exactly  at  the  marks,  as  shown  at  /,  thus  leaving  the  small 
hole  e  in  the  exact  center  of  the  wooden  cross  which  in  turn  fits 
snugly  into  the  cylinder  counterbore. 

ADJUSTING  THE  CENTER  LINE. 

The  line  c  d,  Fig.  126,  consisting  of  a  string  or  a  wire,  has 
been  passed  through  hole  e,  Fig.  125,  knotted,  then  threaded 
through  the  cylinder,  from  which  it  passes  out  by  means  of  the 
rod  hole  and  gland  as  shown  by  Fig.  126,  the  free  end  of  the  line 
being  attached  to  a  target  and  pulled  tight.  The  problem  now 
becomes  twofold.  The  line  must  be  centered  in  the  gland  of  the 
stuffing  box  by  means  of  a  pair  of  inside  calipers  which  are  applied 


FIG.  126.— CENTERING  LINE  IN  GLAND. 

as  shown  at  a,  and  also  applied  at  b,  the  position  of  the  engine 
bed  being  adjusted  until  the  line  c  d  lies  as  close  to  the  center  of 
the  gland  as  human  skill  can  determine.  This  is  one  part  of  the 
problem.  The  other  is  to  maintain  the  line  in  its  position  in  the 
center  of  the  cylinder,  and  at  the  same  time  so  move  the  engine 
bed  that  the  line  a  b  shall  be  brought  perpendicular  to,  or  "square 
with"  the  main  shaft  line. 


334  MILL  WEIGHTING 

If  the  alining  and  measuring  have  been  accurately  done,  the 
templet  properly  located,  and  the  anchor  bolts  set  without  having 
been  moved  out  of  place,  then  there  should  not  be  more  than  a 
quarter  of  an  inch  movement  necessary  in  the  engine  bed  in  order 
to  bring  the  line  a  b  to  coincide  with  the  building  line,  or  to 
square  the  shaft  line.  It  might  well  be  said  that  the  problem  was 
a  triple  instead  of  a  double  one,  for  the  level  of  the  engine  bed 
has  to  be  maintained  while  it  is  being  brought  into  line  with  the 
shaft. 

Some  engine  builders  have  simplified  this  lining-np  business 
a  great  deal  by  casting  a  couple  of  lugs  on  the  engine  bed.  These 
lugs  are  machined  at  the  time  the  cylinder  and  guides  are  bored, 
thus  making  it  only  necessary  to  line  up  the  two  finished  lugs, 
and  the  cylinder  will  be  in  its  proper  position. 

FASTENING  THE  ENGINE  BED  IN  POSITION. 

The  engine  bed  having  been  accurately  lined  up,  and  tempo- 
rarily supported  in  a  level  position  upon  wedges,  as  described  for 
machines,  on  page  267,  chapter  XIV,  proceed  to  put  in  cement, 
brimstone  -or  lead  as  there  described,  after  which  the  anchor  bolt 
nuts  may  be  tightened.  Another  test  should  be  given  with  level 
and  inside  calipers,  after  the  anchor  nuts  have  been  tightened,  to 
see  if  anything  has  been  pulled  out  of  line  or  level  by  the  tight- 
ening of  the  nuts.  Sometimes  this  happens,  but  not  often,  and 
never  if  the  wedging  and  filling  under  the  bed  has  been  properly 
done.  If  one  portion  of  an  engine  bed  is  pulled  out  of  place  by 
the  foundation  bolts  it  is  convincing  evidence  that  the  foundation 
has 'not  been  properly  built,  or  that  the  bed  casting  has  not  been 
properly  fitted  to  the  foundation.  In  any  instance  it  means  "inves- 
tigate," and  do  the  work  over  again  until  it  will  pass  the  inspec- 
tion of  screwing  down  upon  the  anchor  bolts. 

SQUARING  THE  ENGINE  SHAFT. 

The  shaft  should  be  alined  to  the  mill  shafting  by  one  of  the 
methods  already  described  and  it  should  be  checked  to  the  line 
drawn  through  the  cylinder.  A  method  for  doing  this  is  shown 
by  Fig.  127,  in  which  a  b  is  a  portion  of  the  line  through  the 
cylinder,  and  c  d  represents  the  center  line  of  the  engine  shaft, 
which  should  be  revolved  until  the  wrist-pin  c  is  brought  as  close 


ERECTING  STEAM  ENGINES  335 

as  possible  to  the  line  without  touching.  While  in  this  position 
the  distance  to  the  fixed  collars  on  the  wrist-pin  is  measured  with 
a  steel  scale  or  with  the  inside  calipers.  The  line  b  should  be 
equidistant  between  the  fixed  collars  on  the  wrist-pin,  as  shown 
at  e. 

After  making  this  measurement,  the  engine  shaft  should  be 
revolved  carefully  until  the  wrist-pin  again  comes  almost  to  the 
line  a  b,  as  at  /.  Here  the  distance  to  each  collar  is  again  care- 
fully measured,  and  if  equal  to  the  measurements  made  at  e,  then 

Id 


FIG.    127.— CHECKING   ALIGNMENT    OF   ENGINE    SHAFT. 

the  shaft  c  d  is  "square"  with  line  a  b,  and  consequently  is  square 
with  the  engine.  If  the  measurements  at  e  and  /  cannot  be  made 
to  agree,  and  to  equal  each  other,  then  something  is  wrong,  and 
the  millwright  must  "take  it  out  and  look  at  it"  until  the  error  is 
found  and  corrected. 

Sometimes  the  distance  e  f  is  increased  by  keying  the  connect- 
ing rod  tight  to  the  wrist-pin,  and  then  measuring  from  the  cross- 
head  end  of  the  rod  instead  of  from  the  wrist  pin.  Then  revolve 
the  engine  shaft  as  before,  and  measure  again.  Usually,  the 
wrist-pin  measurement  is  all  that  will  be  necessary. 

ADJUSTING  THE  MAIN  BEARINGS. 

It  is  a  matter  of  great  importance,  both  when  setting  up  the 
engine  as  well  as  when  tightening  the  main  bearings,  to  make  sure 
that  the  shaft  is  and  remains  "square"  as  above  described,  also 
that  the  wear  of  the  main  journals  does  not  cause  the  piston  to 
approach  one  head  of  the  other  so  close  as  to  strike  it.  Some- 
times a  knock  which  is  very  hard  to  locate  is  caused  by  one  head 
being  touched  by  the  piston. 


336  MILLWRIGHTING 

The  clearance  at  either  end  of  the  cylinder  should  be  watched 
very  closely  while  making  up  the  main  bearings.  Not  only  should 
the  clearance  be  equalized,  but  it  should  be  kept  equal,  not  only 
when  making  up  the  bearings,  but  when  taking  them  up  against 
ordinary  wear.  Place  the  main  bearing,  also  the  outboard  bear- 
ing, in  the  center  of  the  housing;  then  test  the  clearance.  This 
may  be  done  in  two  ways,  the  first  of  which  is  to  procure  a  bit  of 
mirror — a  pocket  mirror  will  do  and  may  be  kept  for  the  pur- 
pose— and  prepare  it  by  removing  the  silvering  from  a  spot  in 
the  center  of  the  glass  about  %  mc^  m  diameter. 

EQUALIZING  THE  CLEARANCE. 

Place  a  light  close  to  one  end  of  the  cylinder,  remove  the  plugs 
from  the  indicator  holes,  and  with  the  glass  in  front  of  the  eye 
and  looking  through  the  hole  in  the  mirror  throw  a  beam  of 
light  into  the  indicator  pipe  hole  and  observe  the  distance  between 
the  piston  and  the  cylinder  head  when  the  crank  is  on  the  center. 
Make  a  similar  observation  at  the  other  end  of  the  cylinder ;  then 
move  the  quarter  boxes  in  the  main  bearings  until  the  observed 
distances  between  piston  and  heads  are  equal  to  each  other. 

The  author  much  prefers  the  second  method  of  determining  the 
clearance  between  piston  and  heads,  which  is :  Insert  in  each  indi- 
cator pipe  hole,  or  in  the  cylinder  drip  holes  if  there  are  no  indi- 
cator openings,  a  piece  of  soft  lead  wire  or  small  lead  pipe  as 
large  as  will  go  into  the  openings  in  question.  Turn  the  engine 
pulley  until  the  crank  has  been  on  the  center  in  either  direction, 
then  withdraw  the  pieces  of  lead  and  note  if  they  have  both  been 
flatted  to  the  same  thickness.  If  they  have  not,  move  the  shaft 
in  the  proper  direction  one-half  the  difference  of  thickness  of  the 
two  pieces  of  lead. 

Care  must  be  taken  in  flattening  the  pieces  of  lead  not  to  allow 
them  to  project  too  far  into  the  cylinder,  less  the  lead  should  be 
flatted  out  so  wide  that  it  could  not  be  withdrawn  through  the  indi- 
cator pipe  hole.  This  would  happen  were  the  piston  too  close  to 
one  end  of  the  cylinder.  A  little  care  in  this  direction  will  prevent 
fastening  the  lead  in  the  holes.  Sometimes  when  lead  is  not  handy, 
a  soft  wood  stick  may  be  used  instead.  The  flatting  of  the  wood 
must  be  quickly  noted,  less  it  springs  back  and  leads  the  observer 
to  believe  that  more  room  is  present  than  really  exists.  Agai»,  it 


ERECTING  STEAM  ENGINES 


337 


is  possible  to  place  the  engine  on  the  dead  center  and  test  the  near- 
ness of  the  piston  with  a  thin  wedge  inserted  through  the  indicator 

pipe  hole. 

\ 

PUTTING  ON  THE  ENGINE  PULLEY. 

When  an  engine  pulley  is  cast  in  one  piece,  it  is  usually  best 
to  roll  it  into  place  and  block  up  underneath,  high  enough  to  per- 
mit the  shaft  to  be  pushed  through  the  pulley.  But  when  a  split 
pulley  is  to  be  erected,  if  two  sets  of  hoisting  tackle  are  available, 
one  may  be  arranged  for  each  half  of  the  pulley,  and  both  pieces 
hung  up  together.  But  when  there  is  only  one  hoisting  rig  avail- 
able, then  a  little  rigging  up  will  be  necessary  in  order  to  handle 
a  heavy  split  engine-pulley. 


FIG.    128.— PUTTING  ON  A   SPLIT  PULLEY. 

First,  make  a  hitch  on  the  half  of  the  pulley  which  carries 
the  keyseat,  and  hoist  away  until  the  pulley  is  in  the  position 
shown  by  sketch  A,  Fig.  128.  The  hitch  is  made  around  one  of 
the  arms  in  order  that  the  split  line  of  the  pulley  may  stand  at 
about  60  degrees  with  the  floor  line,  as  shown.  If  in  doubt  about 
one  of  the  arms  being  strong  enough  for  a  hitch,  put  one  end  of  a 
rope  sling  around  arm  a,  the  other  end  of  the  sling  around  arm  b, 
taking  care  to  arrange  the  pull  on  opposite  sides  of  the  arms  so 
that  the  edges  of  the  pulley  will  hang  vertical. 

When  almost  in  place,  lay  in  the  key  or  feather  and  block  at  d, 


338  MILLWRIGHTING 

then  take  another  pull  on  the  hoist  and  block  at  e.  Place  another 
block  at  g,  build  across  each  side  of  the  pulley  to  carry  posts  c> 
then  drive  double  wedges  on  each  side  of  the  pulley  at  /,  and  the 
pulley-half  is  in  place  and  will  stay  there  when  the  tackle  is 
removed.  Next  make  a  hitch  on  the  remaining  half  of  the  pulley 
as  shown  by  sketch  B,  Fig.  128,  and  swing  the  remaining  half  of 
the  pulley  into  place.  If  the  hitch  is  made  at  the  right  point,  the 
pulley-half  will  go  up  at  just  the  right  angle  to  fit  on  the  first  half 
of  the  pulley.  If  this  angle  is  not  quite  right,  let  the  rim  come 
together  at  one  split — no  matter  whether  upper  or  lower;  then 
drop  in  a  bolt  and  the  rim  can  be  lowered  in  place  without  the 
least  danger  of  a  slip.  If  the  angle  be  so  great  that  one  of  the 
regular  rim  bolts  cannot  be  put  in  place,  then  slip  a  small  bolt  in 
temporarily.  Almost  anything  will  hold  the  slight  strain  until  the 
pulley-half  is  fairly  in  place,  when  the  regular  bolts  may  be  sub- 
stituted for  the  temporary  ones  and  screwed  home  for  keeps. 

TIGHTENING  PULLEY  BOLTS  AND  LINKS. 

It  is  sometimes  found  that  the  bolts  which  hold  together  the 
halves  of  a  split  pulley  cannot  be  made  to  stay  tight.  One  or  more 
of  the  nuts  persist  in  working  loose,  no  matter  what  may  be  done 
to  them.  When  a  case  of  this  kind  is  met  with,  the  matter  may  be 
settled  for  all  time  by  heating  the  bolts  before  putting  them  in 
place  and  screwing  them  home  while  hot. 

A  red  heat  is  not  needed  for  this  purpose.  There  is  danger  of 
breaking  off  the  lugs  or  of  cracking  the  rim  if  the  bolts  are  heated 
too  hot.  A  black  heat  is  sufficient,  and  the  bolts  should  all  be  put 
in  place  cold,  or  other  bolts  may  be  thus  put  in  and  screwed  home ; 
then  they  are  removed  one  at  a  time,  the  heated  bolts  substituted 
and  screwed  home  as  fast  as  they  are  put  in  place.  No  waiting  to 
give  a  turn  on  each  nut  in  succession,  in  this  case.  Be  sure  that 
the  pulley  is  well  matched  up  where  split,  and  held  there  by  the 
temporary  bolts ;  then  put  in  the  hot  ones,  one  at  a  time,  and  screw 
them  tight  as  quickly  as  possible. 

When  a  pulley  with  a  heavy  rim  is  used,  either  as  a  belt  wheel 
or  as  a  balance  wheel,  it  is  often  necessary  to  use  links  or  dove- 
tailed bars  for  fastening  the  split  sections  together  more  strongly 
than  can  be  done  with  bolts.  In  cases  of  this  kind,  the  links  may 
be  heated,  then  slipped  in  place  and  allowed  to  cool.  The  only 


ERECTING  STEAM  ENGINES  339 

trouble  about  this  method  comes  when  it  is  necessary  to  get  the 
links  out  again — but  as  we  are  not  bothering  about  that  part  of 
the  business,  the  man  who  wants  to  get  them  out  can  drill  holes 
in  the  links  of  do  any  other  fancy  stunt  he  pleases  with  them.  If 
too  loose,  he  can  slip  a  bit  of  sheet  iron  inside  the  hot  link,  and  it 
will  be  as  tight  as  you  please  when  it  cools. 

PUTTING  ON  THE  ENGINE  BELT. 

While  engine  belts,  may  be,  and  are,  fastened  in  various  ways, 
there  is  but  one  method  which  should  be  used  when  the  best  possi- 
ble results  are  required,  and  that  method  is  the  cement  splice. 
Put  a  first-class  short  lap  leather  belt  on  the  engine  and  make  the 
belt  endless  by  splicing  the  ends  together.  When  the  belt  stretches 
so  much  that  it  slips,  then  make  a  new  splice,  but  the  second  one 
will  run  for  five  years  without  further  attention  except  to  keep 
the  belt  in  proper  condition  by  cleaning  and  oiling  it  as  required 
by  the  service  the  belt  must  give. 

Never  attempt  to  "run-on"  an  engine  belt.  No  belt  over  8 
inches  wide  should  ever  be  placed  upon  its  pulleys  by  running  the 
belt  over  the  edge  of  a  pulley  after  the  belt  has  been  fastened 
together  to  its  proper  length.  Use  a  set  of  good  belt  clamps  and 
be  sure  to  get  a  set  which  will  not  slip.  If  forced  to  use  clamps 
which  slip,  never  nail  on  a  bit  of  a  cleat  to  stop  the  slip.  Instead 
of  this  outrageous  proceeding,  do  as  described  on  page  255,  chap- 
ter XIII.  Belt  clamps  are  now  made  with  malleable  ribbed  jaws 
so  braced  that  they  will  not  yield  in  the  middle  of  the  belt.  The 
screws  are  also  cross-connected  so  both  nuts  may  be  turned  at  the 
same  time  by  means  of  a  crank.  Several  clamps  should  be  secured 
so  as  not  to  have  to  put  together  large  and  small  belts  with  the 
same  clamp. 

THE  GOVERNOR  BELT. 

The  governor  belt,  though  very  narrow,  is  fully  as  important 
as  the  engine  belt,  and  it  should  be  put  together  with  a  cement 
splice  also.  No  engine  will  run  as  steady  and  regulate  as  closely 
with  a  rough,  uneven,  lumpy  regulator  belt  as  it  will  with  a  belt 
which  is  endless,  smooth  and  straight. 

The  millwright  may  easily  demonstrate  this  matter  to  his  satis- 
faction and  to  that  of  his  employer.  All  that  is  necessary  is  to 


340  MILLWRIGHTING 

attach  a  light  wooden  pointer  to  the  governing  device  of  the 
engine,  as  represented  by  a,  Fig.  129.  The  pointer  is  fulcrumed 
at  b,  and  wood  enough  to  balance  the  weight  of  arm  a  is  left,  as 
shown  to  the  left  of  fulcrum  b.  A  light  link  is  used  for  attaching 
the  pointer  at  c  to  the  moving  sleeve  of  the  engine  governor.  The 
radius  b  c  is  made  as  short  as  possible  and  have  c  travel  with  the 
regulator  sleeve. 


FIG.    129.— TESTING    A    GOVERNOR    BELT. 

When  the  engine  is  up  to  speed,  the  manner  in  which  point  d 
dances  around  every  time  an  inequality  of  the  belt  passes  the 
governor  pulley  will  be  a  revelation  to  the  man  who  has  never 
tried  this  interesting  experiment.  Try  it  with  an  endless,  smooth 
belt,  then  with  a  crooked,  patched-up  belt  with  lace  leather 
bunches  in  one  or  more  places,  and  it  is  safe  to  say  that  you  will 
never  use  anything  except  the  best  governor  belt  obtainable,  and 
cemented  together,  at  that. 

RUNNING  "OVER"  OR  "UNDER." 

It  used  to  be  the  desire  of  every  engineer  to  have  an  engine 
run  "over,"  or  "forward."  Nowadays  there  is  little  attention  paid 
to  the  direction  in  which  an  engine  is  to  run  as  they  are  con- 
structed to  run  equally  well  in  either  direction,  and  the  crosshead 
wear  is  about  the  same,  no  matter  which  way  the  engine  runs. 


ERECTING  STEAM  ENGINES  341 

There  is,  however,  one  point  in  connection  with  this  matter 
which  the  millwright  should  not  lose  sight  of,  and  that  is,  shall  the 
engine  be  belted  "forward"  or  "backward?"  In  other  words,  is 
the  belt  to  lead  away  from  the  wheel  into  space,  or  is  the  belt  to 
extend  backward  past  the  cylinder? 

The  difference  here  is  not  in  the  manner  in  which  the  engine 
will  run  with  the  belt  in  either  direction,  but  it  is  in  the  change 
of  construction  made  necessary  in  some  cases  when  the  engine 
is  to  be  belted  "backward."  The  reason  for  this  is,  that  some 
engines,  particularly  those  of  the  Corliss  type,  are  so  designed 
that  when  the  engine  is  to  be  belted  backward  the  shaft  must  be 
increased  a  foot  or  more  in  length  in  order  that  the  belt  may  not 
interfere  with  things  at  the  cylinder.  Thus  it  stands  the  mill- 
wright to  look  out  for  this  matter  when  he  is  considering  tjie 
resetting  or  re -location  of  an  engine,  or  of  obtaining  a  new  one  to 
fit  into  a  certain  position. 

WATER  SEPARATOR  AND  CYLINDER  LUBRICATOR. 

Every  steam  engine,  no  matter  how  large  or  how  small,  should 
be  fitted  with  a  separator  in  the  pipe,  close  to  and  on  the  boiler 
side  of  the  throttle  valve.  Water  is  sure  to  come  over  in  greater 
or  less  quantity  with  the  steam,  and  a  good  separator  will  prevent 
such  entrained  water  from  passing  into  the  engine  cylinder  to 
the  possible  damage  or  destruction  of  that  useful  portion  of  the 
engine. 

Every  separator  must  be  fitted  with  a  drip  large  enough  to 
carry  away  all  the  water  which  comes  along,  and  the  drip  should 
be  connected  into  a  good  trap  which  will  get  rid  of  the  water 
without  wasting  steam.  Hand  operation  of  a  steam  separator,  by 
"bleeding"  the  appliance  occasionally  by  hand,  should  never  be 
depended  upon.  The  "bleeding"  is  sure  to  be  forgotten,  and  a 
separator  full  of  water  is  worse  than  no  separator  at  all. 

The  cylinder  lubricator  should  always  be  selected  from  the 
double  sight  feed  types,  giving  a  sight  of  the  oil  as  it  passes  to 
the  cylinder,  also  a  sight  of  the  condensed  water,  in  another  feed 
glass,  as  it  passes  into  the  oil  reservoir  to  displace  an  equal  volume 
of  the  lubricant.  When  connecting  up  a  sight  feed  lubricator  for 
the  cylinder,  do  not  make  the  mistake  of  using  too  short  a  pipe  in 
which  steam  may  condense  to  feed  the  lubricator.  Do  not  tap  in 


342  MILLWRIGHTING 

the  pipe  in  question  below  the  separator.  Tap  it  in  above  that  appli- 
ance if  you  want  to,  and  get  plenty  of  condensing  steam  length. 
And  never  make  the  mistake  of  connecting  the  lubricator  to  the 
steam  pipe  on  both  sides  of  the  throttle  valve.  It  will  not  work 
\vell  if  you  try  it. 

When  attaching  a  single  pipe  lubricator,  it  is  necessary  to 
attach  it  below  the  separator,  but  the  connecting  pipe  should  be  a 
large  one  and  as  long  as  possible.  There  must  be  sufficient  con- 
densing area,  or  the  best  of  lubricators  will  not  work.  On  large 
engines,  do  not  trust  to  one  lubricator.  Put  on  a  force  feed  lubri- 
cator in  addition  to  the  automatic  appliance  and  the  engine  will 
be  safe  no  matter  how  completely  the  automatic  lubricator  may 
"go  bad." 

EXHAUST  AND  DRIP  PIPES,  AND  HEATER. 

Every  exhaust  pipe  from  the  engine  room  should  go  to  the 
heater — that  is,  if  there  is  ever  any  steam  to  escape  through  the 
pipes  in  question— and  there  should  be  adequate  drip  pipes  from 
either  end  of  the  cylinder  and  from  the  steam  pipe  just  above  the 
throttle.  These  three  drips  should  unite  in  a  single  pipe  which  may 
enter  the  exhaust  pipe,  but  the  angles  in  all  these  drips  should  be 
made  of  tees  instead  of  elbows,  with  the  extra  opening  plugged. 
This  makes  a  very  convenient  way  of  getting  into  the  drip  pipes 
in  case  of  stoppage  therein. 

The  exhaust  pipe  from  engine,  also  from  any  pump,  should 
have  an  opening  in  the  lowest  point  of  such  pipe  through  which 
water  may  find  its  way  direct  to  sewer  or  other  waste  outlet.  A 
1-inch  hole  tapped  into  the  elbow  where  the  engine  exhaust  pipe 
makes  its  upward  turn  to  the  heater,  is  a  most  excellent  way  of 
getting  rid  of  condensed  water  in  the  exhaust  pipe  but  never  make 
the  mistake  of  fitting  a  valve  to  the  hole  in  question  which  should 
remain  open  at  all  times,  and  closing  of  it  should  not  be  possible. 
In  a  similar  manner,  there  should  be  left  an  unclosable  opening  or 
drip  from  the  bottom  portion  of  the  exhaust  steam  space  in  the 
heater.  If  back  pressure  is  to  be  carried  in  the  exhaust  pipe,  these 
openings  may  be  water-trapped  to  equal  the  back  pressure  carried, 
but  no  valves  should  ever  be  placed  on  any  of  these  openings. 

The  heater  should  be  selected  with  a  guaranteed  heating  sur- 
face of  one-third  square  foot  to  each  horse-power  of  rated  capa- 


ERECTING  STEAM  ENGINES  343 

city.  Heaters  with  only  one-fourth  square  foot  to  the  horse-power 
are  not  desirable.  The  matter  of  open  or  closed  heaters  must  be 
settled  by  the  designer  of  the  steam  plant.  Personally,  the  author 
favors  the  closed  type,  in  order,  for  one  reason,  to  be  able  to  feed 
with  an  injector  through  the  heater  when  necessary,  something 
not  possible  with  the  open  types  of  feed  water  heaters. 


CHAPTER  XVIII. 

STEAM  BOILER  SETTING. 

The  efficiency  of  a  power  plant  depends  a  good  deal  upon  the 
boilei";  not  only  upon  its  efficiency  as  a  steam  generator,  but  upon 
the  location  and  manner  in  which -it  is  erected.  A  boiler  may  be 
so  set  that  a  great  deal  of  heat  is  lost  in  the  setting  through  air 
inlets,  cramped  passages  and  poor  heat  circulation,  if  that  term 
may  be  allowed.  In  addition,  there  may  be  serious  losses  due 
to  improper  location  of  the  boilers.  It  may  cost  too  much  to  con- 
vey steam  or  power  to  the  points  of  consumption,  or  the  method  of 
getting  fuel  to  the  boilers  is  a  costly  one.  Again,  the  matter  of 
removing  ashes  is  difficult,  or  the  boiler  may  be  so  located  that 
repairs  become  a  serious  matter,  even  aside  from  the  cost  of 
similar  repairs  to  other  boilers.  And  when  new  boilers  must  be 
put  in,  the  cost  of  removing  the  old  ones  and  substituting  new 
becomes  as  great  or  even  greater  than  the  original  cost  of  the 
boilers  when  new. 

LOCATING  THE  BOILER. 

Boiler  location  is  one  of  the  first  things  which  should  be  done 
when  a  plant  is  projected.  It  should  proceed  closely  with  the 
location  of  the  engine  and  the  other  machinery  in  the  mill.  In 
fact,  the  location  of  the  power  plant  is  one  of  the  most  vexatious 
problems  of  factory  design.  A  balance  must  be  struck  between 
the  cost  of  handling  steam  and  the  transmission  of  power;  the 
matter  of  other  steam  consumption  becomes  a  factor,  such  as  heat- 
ing the  buildings,  drying,  boiling,  and  other  chemical  and  mechani- 
cal operations.  Add  to  all  this  the  problems  outlined  in  the  pre- 
ceding paragraph  and  it  will  be  seen  that  the  location  of  a  steam 
boiler  is  no  small  job,  neither  is  it  an  easy  one.  The  electric  motor 
has  solved  the  problem,  as  it  permits  the  boiler  to  be  put  any- 
where. 

344 


STEAM  BOILER  SETTING  345 

EXCAVATING  FOR  BOILER  FOUNDATION. 

Usually  it  is  not  necessary  to  excavate  very  deeo  for  a  boiler 
foundation.  A  trench  a  foot  or  so  in  depth,  following  the  outline 
of  the  walls  and  across  where  the  bridge  wall  is  to  go,  will  be 
sufficient  in  most  cases.  The  side  walls,  including  the  air  space, 
are  about  30  inches,  and  the  rear  wall,  28  inches.  The  bridge  wall 
is  about  the  same  thickness,  and  the  front  wall  may  be  9  inches 
for  a  half  arch  front,  or  16  to  18  inches  for  a  full  flush  front 
boiler. 

The  trench  filled  with  loose  stones  to  the  level  of  the  ground  is 
all  the  foundation  that  will  be  necessary  in  most  cases,  and  con-, 
crete  for  steam  boilers  seems  hardly  necessary  except  in  cases 
where  the  nature  of  the  soil  demands  a  concrete  foundation. 
When  a  large  number  of  boilers  are  to  be  set  in  battery,  and  the 
posts  of  the  building  are  scattered  among  the  boiler  foundations, 
it  may  be  necessary  to  put  in  heavy  boiler  foundations ;  but  when 
but  one  or  at  the  most  two  boilers  are  to  be  set,  the  loose  stone 
filling  will  almost  always  prove  all  that  is  necessary. 

STARTING  THE  BRICKWORK. 

When  setting  plans  are  to  be  used,  and  that  method  of  boiler 
setting  is  far  preferable  and  should  always  be  followed  if  possible, 
the  boiler  setting  should  be  laid  out  the  same  as  any  other  machine 
foundation,  squared  with  the  building  line,  and  the  excavation 
laid  out  in  the  usual  way.  But  when  plans  have  not  been  fur- 
nished, then  let  the  millwright  and  the  mason  get  their  heads 
together  and  make  a  sketch  of  the  layout,  as  shown  by  Fig.  130 ; 
then  lay  out  the  setting,  excavate  and  fill  the  hole,  leaving  a 
depression  or  pocket  where  the  ash-pit  will  come,  which  should 
be  cemented  water-tight  to  form  a  shallow  pit  in  which  water 
may  be  kept  to  the  depth  of  several  inches  when  the  boiler  is  in 
operation.  When  an  ash-pit  is  thus  prepared,  and  ashes  are  never 
allowed  to  collect  above  the  surface  of  the  water,  the  burning  out 
of  grate  bars  will  be  something  almost  unheard  of.  It  is  the  radia- 
tion of  heat  from  a  pile  of  ash  and  clinker,  close  beneath  the 
grate,  which  causes  the  bars  to  burn  out  so  frequently.  Keep 
water  in  the  pit  at  all  times  and  the  surface  of  the  liquid  will 
always  be  below  212  degrees,  no  matter  how  fierce  a  fire  is  car- 
ried on  the  grate. 


346 


MILLWRIGHTING 


Spread  a  couple  of  inches  of  mortar  over  the  loose  stones 
where  the  brickwork  is  to  be  started,  but  before  this  is  done,  roll 
the  boiler  in  place  and  block  it  securely  in  the  exact  position  it 
is  to  occupy  when  set.  Build  the  supporting  cribwork  of  short 
blocks,  and  use  only  those  small  enough  to  be  passed  easily  out  of 
the  ash-pit  doors  and  the  cleaning  door  in  the  back  combustion 
chamber.  A  long  block  or  a  large  one  is  a  nuisance  which  should 
never  be  tolerated  or  used  in  blocking  under  a  boiler  which  is  to 
be  set. 

Before  starting  the  brickwork,  locate  the  buckstays  and  place 
the  lower  tie  rods  in  position.  Some  masons  omit  the  lower  tie 


FIG.    130.— PLAN   FOR    SETTING   A   HORIZONTAL   TUBULAR   BOILER. 


rods  and  set  the  ends  of  the  stays  in  the  ground  and  cement 
around  them,  but  the  tie  rod  is  much  to  be  preferred  and  should 
be  used  whenever  possible. 

It  is  not  necessary  to  use  cement  mortar  even  in  the  lower 
courses  of  brickwork  of  a  boiler  setting.  Common  lime  mortar 
is  plenty  good  enough,  and  cheaper  than  cement.  Start  the  walls 
as  close  to  measurement  as  possible  and  build  them  solid  a  few 
inches  high.  Then  start  the  air  space  between  the  inner  and  the 
outer  wall,  and  from  the  start  to  the  finish  see  to  it  that  no  header 
is  tied  into  both  walls  across  the  air  space.  Frequent  headers 
should  be  put  in  one  wall  to  barely  touch  the  other  wall,  but  any 
header  must  not  be  built  into  both  walls. 


STEAM  BOILER  SETTING 


347 


FIRE-BRICK  FURNACE  LINING. 

The  furnace  must  be  lined  with  good  fire-brick  independent  of 
the  walls  of  the  boiler  setting,  as  shown  by  Fig.  130  at  a,  a,  also 
at  b,  Fig.  131,  and  at  c,  c,  Fig.  132,  which  also  shows  the  method 
of  tying  the  fire-brick  wall  into  the  other  brickwork.  Build  the 
common  and  fire-brickwork  in  such  a  manner  that  the  latter  can 
be  easily  removed  and  replaced  with  new  bricks,  and  there  will 
be  no  trouble  in  getting  that  part  of  the  setting  just  about  right. 

The  proper  manner  of  locating  the  bridge  wall  and  the  grates 
is  clearly  shown  by  Fig.  131,  the  grate  pitching  a  little  toward  the 


±== 


b- 


FIG.   131.— SIDE  ELEVATION  OF  HORIZONTAL  BOILER  SETTING. 

rear  end,  thus  making  firing  much  easier.  The  bridge  wall  is  a 
subject  of  much  difference  of  opinion  among  power  plant  men, 
some  claiming  that  it  should  be  built  to  a  circle  a  few  inches  from 
the  boiler  shell  in  order  to  "force  the  flame  against  the  shell." 
A  man  is  welcome  to  this  opinion  if  he  wants  it — the  author  does 
not  care  for  it — and  the  bridge  wall  should  be  regarded  as  merely 
for  the  purpose  of  preventing  coal  and  ashes  from  being  pushed 
off  the  back  end  of  the  grate.  That  is  all  the  bridge  wall  is  good 
for,  and  it  should  be  no  higher  than  will  serve  that  purpose,  con- 
sequently the  top  of  the  bridge  wall  should  be  straight  and 
flat. 


348 


MILLWRIGHTING 


LUGS  FOR  SUPPORTING  THE  BOILER. 

The  disposition  of  the  four  lugs  which  support  the  boiler  is 
plainly  shown  at  d,  d,  d,  d,  Fig.  130,  also  at  e,  f,  Fig.  131.  These 
lugs  should  be  riveted  to  the  boiler  shell  upon  a  cross-center  line 
directly  through  the  middle  of  the  boiler.  There  is  a  rule  for 
determining  the  distance  of  the  lugs  from  each  end  of  the  boiler 
in  order  that  equal  weight  may  come  upon  each  pair  of  lugs  with 
the  least  strain  upon  the  shell,  i.e.,  so  that  the  cantilever  effect  of 
the  overhanging  ends  may  balance  the  central  portion  of  the 


FIG.    132.— SECTIONAL   END   VIEW   OF   HORIZONTAL   BOILER   SETTING. 

boiler  between  the  lugs,  to  a  certain  degree.     But  this  concerns 
the  boiler  maker  more  than  it  does  the  millwright. 

The  lug  e,  the  one  at  the  front  end  of  the  boiler,  or  the  pair 
of  lugs  at  that  end,  should  be  set  solid  upon  a  cast-iron  plate, 
which  in  turn  is  solidly,  supported  by  the  wall.  There  should  be 
no  possibility  of  slipping  or  sliding  with  this  pair  of  plates.  The 
pair  of  plates  at  the  rear  end  of  boiler,  one  of  which  is  shown  at 
/,  Fig.  131,  should  have  four  or  more  rolls  interposed  between 
lug  and  plate.  These  rolls  should  be  at  least  one  inch  in  diameter, 


STEAM  BOILER  SETTING  349 

straight  and  round,  and  they  should  be  placed  with  great  care  so 
as  to  be  each  parallel  with  the  other,  and  square  with  the  length 
of  the  boiler.  Should  any  of  the  rolls  be  placed  cornerwise,  it  is 
evident  that  the  boiler  must  slide  over  them  instead  of  rolling 
easily  back  and  forth  as  the  shell  expands  and  contracts. 

The  author  has  seen  boilers  set  with  the  rolls  placed  length- 
wise with  the  boiler,  and  many  more  boilers  may  be  found  with 
no  rolls  at  all.  And  some  are  to  be  found  with  no  plates  between 
brickwork  and  the  lugs.  The  behavior  of  the  boiler  and  its  walls 
under  such  conditions  may  well  be  imagined. 

THE  BACK  ARCH. 

The  back  or  rear  arch  is  shown  at  g,  Fig.  131,  and  the  man- 
ner of  its  support  upon  three  curved  T-irons  is  also  apparent, 
particularly  upon  reference  to  the  dotted  lines  i,  Fig.  132.  It 
will  be  noted  that  the  "spring"  of  the  arch  (the  beginning)  is 
on  the  line  of  the  supporting  lugs,  which  is  also  at  the  center  of 
the  boiler.  The  top  of  the  inside  of  the  arch  is  just  even  with  the 
water  level  which  is  assumed  to  be  carried  in  the  boiler. 

Extra  care  should  be  taken  at  the  end  of  the  back  arch,  h, 
Fig.  131,  to  make  sure  that  no  portion  of  the  brickwork  touches 
the  boiler.  There  must  be  room  for  expansion  between  the  rear 
end  of  shell  and  the  arch,  therefore  it  is  very  necessary  to  leave  a 
space  clear  and  clean  between  the  brick  and  the  boiler.  Mortar  or 
dirt,  falling  into  this  space,  causes  trouble,  and  it  is  well  to  run 
up  the  arch  even  with  the  circle  of  the  boiler  and  at  least  1  inch 
distant  therefrom,  then  lap  a  course  of  brick  onto  the  shell  a 
couple  of  inches.  The  shell  can  slide  underneath  this  course  of 
brickwork,  which  will  prevent  anything  from  falling  into  g  and 
blocking  against  the  free  expansion  of  the  boiler  shell. 

The  rear  wall  is  much  heavier  than  the  front  wall,  and  should 
the  boiler  be  blocked  solid  at  g,  the  expansion  of  the  shell  will 
be  very  apt  to  slide  the  boiler  bodily  forward,  tearing  out  the 
entire  front  masonry  and  cracking  the  setting  in  a  hundred  places. 
This  is  apt  to  be  the  case  when  the  boiler-supporting  lugs  are 
made  in  two  pieces,  one  riveted  to  the  shell,  the  other  piece  slipped 
over  a  dovetail  projection  on  the  first  piece.  This  makes  it  very 
convenient  to  roll  the  boiler  around  when  unloading  or  getting  it 
into  place,  but  look  out.  If  the  slip  casting  is  not  a  very  tight 


350  MILLWRIGHTING 

fit  on  the  riveted  portion  of  the  lug,  then  the  boiler  will  slip 
through  the  lugs  instead  of  rolling  along  on  the  rear  plates,  and 
if  anything  gets  into  space  gf  away  will  go  the  boiler. 

The  author  has  been  caught  once  or  twice  in  this  manner, 
and  will  never  erect  one  of  the  boilers  with  two-piece  lugs  on  it 
without  having  the  blacksmith  make  some  thin  wedges  and  drive 
them  so  tightly  into  the  crack  between  the  two  parts  of  the  head- 
end lugs  that  slipping  there  is  an  utter  impossibility. 

THE  FEED  PIPE. 

Ways  without  number  are  possible  for  the  arrangement  of  a 
feed  pipe  and  its  disposition  inside  the  boiler.  The  author  has 
found  no  better  way  than  that  known  as  "the  Hartford,"  which  is 
represented  as  entering  the  boiler  through  the  front  head  just 
above  the  water  line,  being  shown  at  p,  Figs.  130  and  131.  In 
the  former  engraving,  the  feed  pipe  is  shown  by  dotted  lines  as 
entering  at  p,  passing  along  the  side  of  the  boiler  to  a  point  q, 
about  two  or  three  feet  from  the  rear  head  (as  far  as  possible 
without  getting  tangled  up  among  the  rear-head  braces),  thence 
across  the  boiler  to  the  other  side  at  r.  There,  the  pipe  terminates 
in  an  elbow  which  is  turned  to  look  forward  and  to  discharge 
horizontally  between  the  shell  of  the  boiler  and  the  outside  row 
of  tubes.  The  pipe,  however,  lies  just  above  the  water  line,  in 
the  steam  space. 

No  perforated  pipe  is  necessary.  The  water,  if  pumped  in 
cold,  becomes  pretty  well  warmed  during  its  passage  through  the 
pipe  in  the  steam  space,  and  as  the  discharge  is  in  about  the 
coolest  part  of  the  boiler,  and  so  arranged  that  it  touches  neither 
tube  or  plate,  there  is  little  chance  for  the  feed  water  to  do  dam- 
age of  any  kind.  Fig.  132  shows  two  openings  in  the  boiler, 
one  at  /,  the  other  at  k.  The  feed  pipe  may  be  inserted  through 
either  of  these  openings,  and  the  author  in  specifying  boilers 
always  provides  for  these  openings,  thus  permitting  the  feed  pipe 
to  be  let  into  the  boiler  on  either  side  as  proves  most  convenient. 
The  hole  not  used  is  fitted  with  a  plug. 

THE  BLOW-OFF  PIPE. 

Trouble  with  the  blow-off  pipe  and  cock  has  been  experienced 
since  boilers  were  invented.  The  connection  shown  at  /,  Fig.  131, 


STEAM  BOILER  SETTING  351 

is  about  the  best  which  has  been  devised  for  connecting  the 
blow-off.  The  boiler  should  be  set  with  the  rear  end  about  1  inch 
lower  than  the  front  end,  then  led  out  of  the  setting  by  the 
shortest  possible  route.  Trouble  has  been  experienced  by  the 
blow-off  pipe  burning  off,  and  all  manner  of  protecting  devices 
have  been  devised  and — found  lacking.  Heavy  hydraulic  pipe 
is  sometimes  used  for  the  blow-off,  but  heavy  pipe  burns  out  fully 
as  quick  as  ordinary  pipe — probably  because  there  is  more  of  the 
thick  pipe  to  burn — so  the  best  way  is  to  "let  it  burn"  and  put  in  a 
new  piece  of  pipe  as  required,  keeping  careful  watch,  meanwhile, 
that  the  pipe  is  renewed  before  it  becomes  burned  away  sufficient 
to  rupture  and  empty  the  boiler  of  water.  That  is  a  very  dis- 
agreeable as  well  as  dangerous  accident,  and  it  should  be  closely 
looked  after  and  guarded  against  by  frequent  renewals  of  the 
blow-off  pipe. 

The  blow-off  valve  or  cock  is  another  necessary  nuisance 
around  a  boiler  room.  It  cannot  be  dispensed  with,  hence  it  must 
be  endured.  Several  improved  forms  of  blow-off  cocks  are  on  the 
market  and  the  only  way  is  to  get  two  or  three  of  them  and  use 
one  until  it  leaks,  then  remove  it  for  grinding  in  again,-  and  try 
another  kind.  After  you  have  found  the  valve  which  suits  condi- 
tions the  best,  keep  three  on  hand  all  the  time,  and  replace  and 
regrind  a  valve  as  soon  as  it  is  found  to  leak. 

The  outer  end  of  a  blow-off  pipe  should  never  be  concealed 
in  a  sewer  or  elsewhere  that  the  attendant  cannot  see  at  all  times 
if  there  be  any  leak  through  the  blow-off  valve.  If  it  be  necessary 
to  discharge  into  a  sewer  or  any  other  place  where  the  end  of  the 
blow-off  pipe  will  not  be  in  sight,  then  arrange  the  blow-off  pipe 
so  there  is  a  vertical  length  in  the  boiler  room.  Cut  the  vertical 
length,  and  insert  a  bolted  union  which  is  so  arranged  that  it  will 
separate  at  least  %  inch  when  the  bolts  are  removed.  Always, 
after  blowing  down,  remove  the  bolts ;  place  a  bit  of  tin  between 
the  union  flanges,  and  if  there  be  a  leak,  the  water  will  run  on 
the  floor  where  it  will  be  seen  and  indicate  the  condition  of  the 
blow-off  valve. 

CLEANING  DOOR  AND  BACK  COMBUSTION  CHAMBER. 

The  cleaning  door,  s,  Fig.  13] ,  must  not  be  forgotten.  It  may 
be  located  where  convenient,  either  in  the  side  walls  or  the  back 


352  MILLWRIGHTING 

wall  of  the  boiler,  but  wherever  located,  be  sure  that  it  is  flush 
with  the  floor  of  the  back  combustion  chamber.  There  is  a  con- 
siderable difference  of  opinion  regarding  the  floor  of  this  cham- 
ber, some  preferring  to  leave  it  level  with  the  ground,  while  others 
fill  to  dotted  line  t,  and  pave  with  brick.  The  author  prefers  to 
leave  the  chamber  vacant  to  the  floor  line.  There  is  more  room 
for  dust  and  ashes,  and.no  man  ever  found  that  the  floor  at  t 
effected  more  efficiency  of  operation. 

SAFETY  VALVE  AND  STEAM  PIPE  CONNECTIONS. 

The  safety  valve  should  have  an  opening  into  the  boiler  for  its 
own  special  accommodation.  No  other  pipe  should  be  connected 
to  the  safety  valve  opening.  Sometimes  the  steam  gage  is  con- 
nected by  drilling  a  hole  in  the  nipple  which  connects  the  safety 
valve  with  the  boiler,  but  it  is  better  to  adhere  strictly  to  the  rule 
and  put  nothing  into  the  safety  valve  opening  except  that  valve. 
It  is  but  little  more  trouble  to  tap  directly  into  the  boiler  shell 
for  the  steam  gage  pipe,  and  it  is  better  in  every  way. 

There  should  be  two  necks  on  every  boiler ;  one  for  the  safety 
valve  as  above  described,  the  other  for  the  pipe  connections.  Pipe 
should  be  connected  with  the  boiler  through  an  angle  expansion 
arrangement,  as  described  on  page  321,  chapter  XVI,  and  care 
should  be  taken  that  the  strain  caused  by  expansion  is  so  dis- 
tributed that  it  will  be  absorbed  without  causing  strain  beyond  the 
elastic  limit  of  the  metal  upon  any  flange,  screw-thread  or  any 
fitting. 

STOP  AND  CHECK  VALVES. 

Put  a  good  stop  valve  in  the  main  steam  pipe  as  close  to  the 
boiler  as  possible.  It  is  a  good  rule  to  put  a  valve  in  each  and 
every  pipe  as  close  to  the  boiler  as  possible.  Something  may 
happen  to  the  pipe  or  valves  in  the  distribution  lines,  and  a  good 
valve,  in  perfect  order,  and  located  close  to  the  boiler,  may  save 
life  and  property  in  case  of  accident  or  emergency. 

The  feed  pipe  should  also  have  a  stop  valve  in  it  as  close  to 
the  boiler  as  convenient  for  working  purposes.  This  valve,  as 
indicated  by  ?;?,  Fig.  131,  should  in  all  cases  be  placed  between  the 
check  valve  n  and  the  boiler.  The  reason  is  a  very  simple  one. 
Things  are  continually  happening  to  check  valves,  and  without  a 


_.  STEAM  BOILER  SETTING  353 

stop  valve  between  the  check  and  the  boiler,  there  would  be  no 
way  of  overhauling  the  check  without  drawing  the  fire  and  blow- 
ing down  pressure  in  the  boiler.  Adjacent  to  the  check,  n,  place 
a  unon  Oj  for  checks  frequently  have  to  be  removed  and  then 
the  union  is  in  just  the  right  place  for  that  work. 

A  high-grade  angle  valve  makes  a  good  connection  between 
the  pipe  and  the  boiler.  Formerly,  angle  valves  were  open  to  dis- 
trust, but  lately  this  class  of  valve  has  been  so  greatly  improved 
that  it  is  very  desirable.  It  saves  the  cost  of  an  elbow,  and  locates 
the  stop  valve  just  where  it  ought  to  be — close  to  the  boiler. 
Angle  valves  are  also  very  handy  in  the  feed  pipe.  But  be  sure 
to  get  good  heavy  valves.  Thin  light  ones  are  worthless  and 
should  never  be  purchased  under  any  pretense  whatever. 

GRATES  AND  DOORS. 

The  grate  bars  should  be  selected  for  the  fael  they  are  to 
burn,  and  local  conditions  should  govern  entirely.  A  good  shak- 
ing grate  is  desirable,  and  an  automatic  stoker  is  always  profitable, 
even  on  small  single  boilers. 

Every  door — the  fire  doors,  those  of  the  ash-pit  and  the  tube- 
front,  and  even  the  cleaning  door — should  be  made  to  fit.  Never 
put  up  a  door  which  leaks.  The  air  which  enters  around  a  poorly 
fitted  door  may  lower  the  efficiency  of  the  boiler  many  points. 
Therefore,  when  poorly  fitting  doors  are  found,  fix  them  if  pos- 
sible before  quitting  them.  If  they  are  so  bad  that  they  cannot 
be  fixed  properly,  then  "bust  'em"  and  get  some  new  doors.  It 
will  be  money  saved,  even  if  the  purchaser  of  the  boiler  must  pay 
for  the  new  doors. 

THE  STACK  AND  THE  DAMPER. 

Modern  tendency  is  toward  the  use  of  the  steel  stack  in  place 
of  the  costly  chimney.  If  possible,  arrange  the  stack  to  stand 
upon  a  foundation  of  its  own.  Even  a  75-foot  stack,  erected  on 
top  of  a  boiler,  exerts  too  much  strain  upon  the  brickwork  of  the 
boiler,  especially  during  high  winds.  The  front  wall  of  a  boiler 
setting  is  always  the  weakest  part  of  the  setting,  on  account  of 
the  large  opening  necessary  for  cleaning  the  tubes,  this  opening 
being  covered  by  the  cast-iron  front,  but  leaving  a  very  weak 
foundation  for  a  superimposed  stack.  If  a  stack  must  be  used, 


354  MILLWRIGHTING 

see  that  the  stack  plate  is  ample  to  give  a  good  bearing  upon  the 
brickwork. 

See  that  the  stack  is  well  supported  by  numerous  guy  cables. 
If  it  be  not  looked  after,  when  the  stack  is  obtained  upon  contract, 
the  guy  cables  sent  will  resemble  clothes  lines  more  than  stack 
guys,  and  heavier  cables  must  be  procured.  Wire  rope  only  ^ 
inch  in  diameter  is  too  light  for  guying  boiler  stacks. 

Stacks  obtained  from  some  manufacturers  are  made  of  mere 
sheet  iron  instead  of  tank  steel.  A  stack  No.  14  gage  is  hardly 
worth  setting  up.  It  is  much  better  to  pay  a  few  dollars  more  for 
No.  10  gage  plate  and  obtain  a  stack  which  will  last  five  years 
at  least.  No.  8  is  none  too  heavy  for  a  stack  which  is  to  last  a 
long  time  without  repairs. 

Always  specify  that  a  damper  be  placed  in  the  stack,  or  in  the 
uptake  to  each  boiler.  When  two  or  more  boilers  are  set  in  bat- 
tery, there  should  be  a  separate  damper  to  each  boiler  and  another 
damper  in  the  stack  or  main  smoke  flue,  and  this  damper  should 
be  connected  to  a  good  damper  regulator  which  is  actuated  by 
steam  or  water  pressure,  and  which  is  controlled  by  the  steam 
pressure  in  the  boilers.  It  will  pay  to  add  a  damper  regulator, 
actuated  by  outside  energy,  to  the  smallest  steam  boiler  which 
may  be  erected  for  economical  use. 

BOILER  FEEDING  APPLIANCES. 

The  belt-driven  pump  is  the  cheapest  boiler  feeder,  the  duplex 
steam  pump  the  more  costly.  The  injector  has  the  least  efficiency, 
when  regarded  as  a  pump,  of  all  water  forcing  appliances,  but  as 
the  heat  efficiency  of  the  injector  is  nearly  100  per  cent.,  that 
quantity  is  sufficient  to  offset  the  low  pump  efficiency  and  to 
place  the  injector  on  the  list  as  a  good  emergency  feeder.  The 
centrifugal  pump  is  about  to  enter  the  boiler  feeding  field.  This 
pump  is  being  made  in  a  form  known  as  the  "multi-stage,"  and 
a  number  of  pumps  on  the  same  shaft  work  the  same  water,  one 
after  the  other,  thus  obtaining  any  required  amount  of  pressure 
without  any  given  rotor  having  to  work  against  more  than  40  to 
60  pounds  pressure. 

The  millwright  should  secure  a  good  back-geared,  belt-driven 
power  pump  and  feed  the  boilers  with  it.  If  electric  trans- 
mission is  employed  in  the  factory,  put  in  an  electrically  driven 


STEAM  BOILER  SETTING  355 

feed  pump  and,  if  possible,  obtain  outside  "emergency  current" 
which  can  be  used  at  any  time  by  merely  operating  a  double- 
throw  switch  to  feed  the  boilers  when  the  factory  engine  is  not 
running. 

CONNECTING  THE  INJECTOR  AND  THE  PUMPS. 

When  setting  up  a  steam  pump,  place  that  appliance  in  the 
middle  of  a  room  where  you  can  get  all  around  it.  A  pump  is 
often  put  into  a  corner  where  it  cannot  be  gotten  at  without  stand- 
ing on  one's  head  and  then  working  in  the  dark.  Build  up  a  pier 
at  least  30  inches  high,  and  place  the  pump  on  top  of  it.  It  is 
foolish  to  put  a  little  pump  down  in  the  dirt  and  then  break  your 
back  in  stooping  down  to  get  at  it.  Put  the  pump  up,  put  it  irf 
the  middle  of  the  room,  and  your  pump  troubles  are  all  gone 
forever. 

Hang  the  injector  from  the  ceiling  or  from  an  overhead 
timber.  Never  put  it  against  the  wall  or  in  a  corner  where  you 
can't  see  or  get  at  the  thing.  Hang  it  up  in  full  view  where 
you  can  get  a  wrench  upon  any  part  of  it  without  skinning 
knuckles  or  jamming  fingers.  Put  a  valve  and  a  union  in  every 
pipe  leading  to  pump  or  injector,  then  you  can  disconnect  any 
fitting  you  wish  without  having  steam  or  water  blowing  through, 
and  without  the  exhaust  backing  up  to  take  a  fellow  in  the  rear. 

Likewise,  put  the  belted  pump  where  you  can  find  it  when 
packing  is  necessary.  There  is  plenty  of  room  out  of  that  corner 
for  the  power  pump.  Put  it  in  the  open,  and  spend  many  a  happy 
hour  kicking  because  you  did  not  do  so  before.  Put  a  by-pass 
connection  around  the  power  pump  so  that  it  (the  pump)  may 
be  run  all  the  time,  and  any  required  quantity  of  water,  up  to  the 
pump  capacity,  may  be  turned  into  the  boiler  in  a  continuous 
stream. 

In  a  large  plant,  everything  should  be  cross-connected.  The 
pumps  should  be  so  piped  that  they  can  be  made  to  force  water  in 
any  line  of  pipe  in  the  mill  by  setting  certain  valves.  The  injec- 
tor shall  likewise  be  cross-connected  to  deliver  to  boiler,  to  tank, 
or  to  other  desired  points. 

The  steam  and  water  shall  also  be  cross-connected,  so  that 
steam  may  be  admitted  to  certain  water  pipes,  and  water  to  cer- 
tain steam  pipes  when  necessary.  This  applies  to  the  connection 


356  MILL  WEIGHTING 

for  blowing  boiler  tubes  with  a  hose  connection.  When  cleaning 
up  a  boiler,  it  is  sometimes  very  handy  to  be  able  to  turn  water 
pressure  into  the  steam  connection,  also  to  turn  either  water  or 
steam  into  the  ashpit.  There  should  be  two  or  more  sources  of 
water  supply,  and  cross-connecting  these  sources  should  always 
be  done. 

In  large  plants,  a  system  of  cross-connecting  the  piping  as 
above  described  should  be  carefully,  designed  and  carried  out, 
but  in  a  small  plant,  much  cross-connecting  is  apt  to  lead  to  con- 
fusion, hence  the  piping  should  be  made  as  "fool-proof"  as  pos- 
sible, and  that  means  that  there  should  be  only  one  way  of  doing 
anything,  and  that  one  way  should  be  so  obvious  that  it  will  hit 
the  attendant  between  the  eyes  if  he  fails  to  see  it  first ! 

THE  AUTOMATIC  BOILER  FEED. 

In  certain  kinds  of  manufacturing,  where  much  steam  is  used 
outside  the  engine,  an  automatic  boiler  feeding  device  may  be  used 
to  advantage.  This  device  consists  of  a  receiver  into  which  flows 
the  several  drips  which  are  to  be  returned  to  the  boiler.  A  float 
valve  in  the  receiver  controls  the  steam  supply  of  a  feed  pump 
mounted  upon  the  receiver  and  as  fast  as  the  water  collects  in  the 
receiver  is  automatically  returned  to  the  boiler.  By  arranging 
a  receiver  as  above,  and  attaching  the  float  valve  to  operate  the 
by-pass  valve  instead  of  a  steam  pump  supply  valve,  the  water  will 
be  returned  automatically  to  the  boiler  by  means  of  the  power 
feed  pump,  at  a  much  less  cost  than  when  the  steam  pump  is  used. 

HIGH  DUTY  BOILER  FEED  PUMPS. 

The  "duty"  of  any  pump  is  the  number  of  foot  pounds  of  work 
done  by  the  pump  for  each  100  pounds  of  coal  burned.  The  new 
unit,  as  proposed,  is  the  work  done  by  one  million  heat  units  fur- 
nished by  the  boiler.  This  rating  is  the  most  just,  as  it  cuts 
out  the  variation  due  to  the  different  values  of  coal  and  also  elimi- 
nates boiler  efficiency,  thus  putting  only  the  efficiency  of  the  pump 
into  consideration. 

While  the  average  duplex  boiler  feed  pump  has  a  duty  of  only 
about  15,000,000  foot-pounds  to  100  pounds  of  coal  burned,  the 
engine  driven  pump  has  a  duty  of  100,000,000  to  140,000,000, 
and  the  steam  pumps  found  in  ordinary  steam  boiler  f eedino-  have 


STEAM  BOILER  SETTING  357 

a  duty  of  only  4,000,000  to  8,000,000  pounds.  The  injector  has 
a  duty  ranging  from  161,000  to  2,752,000.  While  the  duty  of 
large  pumping  engines  is  high,  the  duty  of  small  steam  pumps  can 
never  be  large,  therefore,  there  are  no  high  duty  boiler  feed  pumps 
in  small  sizes,  except  those  driven  from  large  engines,  the  duty 
of  the  pump  being  that  of  the  engine  driving  it. 

STEAM  TRAPS. 

Every  drip  or  outlet  designed  to  permit  water  to  escape  with- 
out the  loss  of  steam  should  be  provided  with  a  trap  which  is 
adjusted  to  the  pressure  of  steam  to  be  carried.  Traps  may  be 
roughly  divided  into  two  classes — those  in  which  the  weight  of 
the  water  actuates  the  discharge  valve,  and  those  in  which  valve 
control  is  affected  by  expansion  and  contraction  of  metals  under 
varying  temperatures. 

The  gravity  traps  need  adjustment  of  valve  opening  and 
weight  of  float  or  kettle  to  fit  them  to  work  against  different 
pressures;  hence,  when  ordering  traps,  the  pressure  should  be 
stated.  Otherwise,  the  millwright  must  change  the  diameter  of 
the  steam  opening,  or  weight  the  kettle  in  order  to  make  the  trap 
work  at  the_  pressure  carried. 

COAL  AND  ASH  HANDLING. 

As  stated  on  page  344  of  this  chapter,  the  question  of  fuel  and 
ashes  should  be  considered  when  locating  the  boiler ;  yet,  no  mat- 
ter how  well  placed  the  plant  may  be,  there  should  be  provided 
adequate  means  for  handling  coal  and  for  removing  the  ashes. 
Various  conditions  require  vastly  different  methods,  but  there 
are  very  few  plants  where  the  conveyor-elevator  cannot  be  profit- 
ably installed  for  bringing  in  coal  and  carrying  out  ashes,  the 
same  apparatus  serving  both  operations,  and  permitting  the  coal 
storage  and  ash  dump  to  be  located  at  will,  either  op  the  ground 
adjacent  to,  or  removed  from  the  building,  or  overhead  in,  or 
outside  the  boiler  house. 

The  first  cost  of  an  installation  of  this  kind  is  comparatively 
low,  and  once  installed  it  will  run  for  years  with  little  cost  for 
repairs  or  renewal.  Therefore,  apparatus  of  this  kind  should 
always  be  considered  in  connection  with  a  steam  plant,  no  mat- 
ter whether  for  100,  or  for  100,000  horse-power ! 


CHAPTER  XIX. 

SOME  SHOP  WORK. 

The  millwright  must  be,  and  usually  is,  prepared  for  any  job 
which  comes  along',,  and  to  be  confronted  with  a  job  of  roll  mak- 
ing is  nothing  but  what  might  be  expected.  In  some  mills,  paper 
manufactories  for  instance,  rolls  are  used  extensively  in  lengths 
from  18  inches  to  10  feet,  and  from  2  to  15  inches  in  diameter. 
The  larger  sizes,  of  course,  are  made  in  the  machine  shop  and  are 
straight  machine  work.  But  there  are  many  small  rolls  to  be 
made  of  wood,  and  it  will  be  assumed  that  the  millwright  is  "up 
against"  two  sets  of  rolls  like  A  and  B,  Fig.  133. 

MAKING  WOODEN  ROLLS. 

The  roll  a  has  a  turned  shaft  passing  clear  through  it  from 
one  end  to  the  other.  In  fact,  the  shafts  were  pieces  cut  from 
cold-rolled  shafting,  1  inch  in  diameter.  The  wood  for  the  rolls 
was  made  from  sapling  pine,  the  round  trunks  being  cut  into 
lengths  as  required  and  worked  while  green.  These  rolls  were 


_TD=» 


B 

FIG.    133.— MAKING    WOODEN    ROLLS. 

about  18  inches  long  and  6  inches  in  diameter.  They  were  bored 
green  as  stated,  then  driven  on  the  shafts  and  allowed  to  season 
before  they  were  turned.  There  was  no  lathe  available  for  this 
job,  hence  the  necessity  for  avoiding  lathework  altogether. 

The  boring  was  done  with  a  single  lip  auger  bit  with  the 

358 


SOME  SHOP  WORK 


359 


worm  filed  off  to  prevent  its  following  the  grain.  To  guide  the 
auger,  and  center  and  hold  the  blocks,  the  rig  shown  by  Fig.  134 
was  devised.  The  bit  was  welded  to  a  long  shank,  "ship  auger" 
style,  and  it  was  mounted  in  two  guides  as  shown,  both  guides 
being  split  to  permit  the  taking  up  of  wear,  should  the  auger  cut 
out  its  guiding  hole  too  much.  These  guides,  a  and  b,  were  bolted 
rigidly  to  the  frame  upon  which  the  rig  was  mounted.  The 
guides  were  lined  up  so  the  auger  would  lie  parallel  with  the 
frame,  then  the  centering  clamps  c  and  d  were  put  in  place  as 
shown,  the  planks  of  which  they  are  composed  being  slotted  as 
shown,  to  permit  a  limited  movement  crosswise  the  frame. 

The  guides  were  lined  up  with  the  centering  clamps  which 
were  cut  off  flush  with  the  outside  of  the  frame  when  they  were 


FIG.  134.— RIG  FOR  BORING  ROLLS. 


central  with  a  6-inch  roll  clamped  between  them.  Thus,  to  center 
a  roll  blank,  it  is  only  necessary  to  put  it  in  place  between  the 
centering  clamps  as  shown  at  g,  and  adjust  clamps  c  f,  and  d  e, 
until  each  projects  the  same  distance  outside  the  frame  timbers 
*  and  ;'.  This  simple  adjustment  centers  the  roll  bolt  both  ver- 
tically and  horizontally,  and  it  is  only  necessary  to  go  ahead  with 
the  rigidly  guided  auger. 

The  shafts  being  1  inch  in  diameter,  and  the  auger  being 
nominally  1  inch  in  diameter,  the  holes  proved  nearly  a  drive 
fit  for  each  shaft.  After  the  shafts  were  driven  home,  the  rolls 
were  laid  away  to  dry,  the  shrinkage  of  the  wood  serving  to  clamp 
itself  very  tightly  against  the  shaft.  The  moisture  and  acid  in 
the  wood  attacked  the  steel  shafts  and  very  quickly  rusted  the 
metal  surface.  This  served  to  increase  the  adhesion  between  roll 


360  MILLWRIGHTING 

and  shaft,  and  not  one  of  them  ever  came  loose  as  long  as  they 
were  under  the  observation  of  the  author. 

Trouble  was  met  with  in  boring  a  few  of  the  holes,  for  the 
auger  evidently  struck  a  wind  shake  or  some  other  imperfection, 
and  the  hole  was  found  to  be  crooked  after  withdrawing  the  auger. 
After  the  shafts  had  all  been  driven,  and  the  rolls  had  dried,  it 
was  found  upon  getting  them  ready  to  turn,  that  the  shafts  had 
been  badly  sprung  in  some  of  the  rolls — probably  those  in  the 
crooked  holes.  Such  shafts  as  were  found  not  to  be  straight 
were  driven  out  and  the  holes  burned  out  until  the  shafts  would 
go  in  and  stay  straight.  This,  of  course,  left  the  holes  much 
larger  than  the  shafts  in  some  places  and  brimstone  was  melted 
and  poured  into  each  end  of  the  rolls  that  needed  this  treatment 

TURNING  ROLLS  WITHOUT  A  LATHE. 

To  turn  these  rolls  to  shape  and  size,  a  couple  of  bearings 
were  rigged  up  to  fit  the  roll  shafts.  One  of  the  smoothest  rolls 
was  mounted  in  another  pair  of  bearings,  end-on  to  the  roll  to  be 
turned.  The  smooth  roll  was  belted  to  a  pulley  which  gave  about 
the  speed  necessary  for  turning  the  rolls.  The  bearings  were  set 
up  underneath  the  pulley  which  chanced  to  give  the  proper 
speed.  As  there  was  no  way  of  stopping  this  improvised  lathe 
spindle,  without  throwing  off  the  belt,  means  had  to  be  provided 
for  making  a  "quick  change"  from  one  roll  to  another. 

To  provide  means  for  stopping  and  starting  the  roll  being 
turned,  a  pin  was  fitted  into  a  collar  so  as  to  project  Vs  inch  from 
one  end  of  the  collar  at  right  angles  to  the  set-screw  and  parallel 
to  the  shaft.  This  collar  was  placed  on  the  overhang  of  the 
shaft  in  the  belted  roll,  the  pin  being  placed  outermost.  A  similar 
collar  was  placed  on  the  end  of  the  shaft  in  the  roll  to  be  turned, 
and  after  that  shaft  had  been  made  up  in  its  bearings  to  run 
without  vibration,  a  push  endwise  on  the  shaft  of  14  inch  caused 
the  two  pins  to  engage  and  the  roll  was  ready  for  turning.  A 
pull  would  cause  the  work  roll  to  stop  at  any  time  for  examina- 
tion or  for  removal,  the  live  "spindle"  running  all  the  time. 

MAKING  LONG  ROLLS. 

Making  short  rolls,  as  shown  at  A,  Fig.  133,  is  an  entirely 
different  proposition  from  making  the  roll  shown  at  B.  This  roll 


SOME  SHOP  WORK  361 

is  of  considerable  length,  and  the  use  of  a  lathe  is  required  in  its 
making.  It  will  be  noted  that  this  roll  has  shouldered  gudgeons, 
also  that  a  ring  is  driven  into  each  end  of  the  roll  to  prevent  the 
splitting  of  the  wood.  The  first  step  is  the  preparing  of  the 
gudgeons,  which  are  merely  pieces  of  round  steel  18  inches  to  2 
feet  long,  and  vary  in  diameter  from  1  to  l1/^  inches  according  to 
the  size  and  length  of  the  roll.  The  gudgeons  are  simply  cut  off 
and  "pointed"  a  little  at  the  ends  with  a  hammer  while  cold,  to 
reduce  the  bur  caused  by  cutting  off. 

The  wooden  portion  is  usually  dry  timber  large  enough  to  turn 
to  the  required  diameter.  Dry  timber  must  be  used  for  this  job 
as  green  stuff  is  not  desirable  at  all.  Cut  the  timber  square,  to 
about  %  inch  longer  than  the  roll  is  to  finish.  The  gudgeon 

b 

i 


a 
FIG.   135.— "POD"  AUGER  FOR  ROLL   BORING. 

holes  may  be  bored  by  chucking  the  bit  and  blocking  up  until  a 
timber  lays  central  with  the  bit ;  then  feed  it  to  the  bit  by  means 
of  the  slide  rest  which  may  be  brought  up  behind  the  timber  as  it 
lays  on  it3  blocking. 

On  one  large  roll  job,  the  author  rigged  a  wood-lathe  center  on 
the  slide  rest,  and  in  bringing  the  rest  up  against  the  roll  the  cen- 
ter was  forced  into  the  intersection  of  diagonals  on  the  end  of  the 
roll  timber,  thus  centering  that  end  without  the  trouble  of  jug- 
gling blockings  at  that  end  of  the  work.  "Pod"  bits  were  found 
best  adapted  for  the  work  of  boring  rolls  in  the  lathe,  and  a  set 
of  the  necessary  sizes  were  kept  for  that  purpose.  Fig  135 
illustrates  this  tool ;  a  section  through  a  b  is  shown  at  c.  A  clean 
straight  hole  can  be  bored  with  a  well  made  tool  of  this  kind. 

BORING  STRAIGHT  HOLES. 

When  rolls  must  be  bored  by  hand,  and  whenever  straight 
holes  are  required  in  other  instances,  the  arrangement  shown  by 
Fig.  136  will  enable  a  careful  workman  to  bore  long  holes  very 
close  to  a  given  direction. 


362  MILLWRIGHTING 

The  timber  in  the  picture  represents  one  of  the  rolls  which  is  to 
be  bored  for  a  gudgeon.  Fasten  in  place  the  two  straight-edges 
a  and  b  by  means  of  a  couple  of  nails  in  each,  taking  care  to  place 
both  strips  exactly  fair  with  the  center  lines  shown  across  the  end 
of  the  stick,  also  to  fasten  each  straight-edge  exactly  parallel  with 
the  timber.  The  man  who  is  boring  has  his  eye  somewhere  near 
d,  and  while  starting  the  auger,  he  will  keep  it  in  line  with  the 


FIG.    136.— METHOD   OF   STRAIGHT   HAND-BORING. 

center-side    of   straight-edge    b,   thus    forcing    the    auger   to    lie 
parallel  with  the  vertical  center  of  the  roll-timber. 

While  starting  the  auger,  let  another  man  place  an  eye  at  c, 
and  sight  the  auger  horizontally  across  straight-edge  a.  This 
alines  the  auger  vertically  to  the  horizontal  center  plane  of  the 
timber,  and  if  these  two  sightings  are  kept  up  until  the  auger  has 
fairfy  started,  there  will  be  little  danger  but  that  the  hole  will  be 
accurately  located  and  bored. 

INSERTING  ROLL-GUDGEONS. 

The  gudgeons  are  simply  driven  into  the  holes  without  any- 
thing further  being  done  to  them,  but  for  rolls  which  are  to  be 
subjected  to  considerable  strain,  a  split-ring  should  be  driven 
into  each  end  of  the  roll  as  shown  by  Fig.  133,  at  a.  A  detail  of 
the  ring  is  shown  by  Fig.  137,  the  complete  ring  being  represented 
at  af  a  section  at  b.  In  making  this  ring,  a  piece  of  thin  flat  iron 
—or  steel  is  flatted  to  a  feather  edge  on  one  side  only,  as  shown 
at  b. 

The  ring  should  be  welded  up  to  a  diameter  about  half  way 
between  that  of  the  gudgeon  and  the  finished  roll.  This  is  for  the 


SOME  SHOP  WORK 


363 


FIG.    137.— SPLIT-RING 
FOR   ROLL-END. 


purpose  of  preventing  any  spatting  action  on  the  part  of  the  ring 
when  it  is  driven  into  the  timber.  With  the  wedge  side  inward, 
the  wood  is  drawn  closer  against  the  gudgeon ;  whereas  if  it  were 
made  up  the  other  side  out,  the  ring  would  act  as  a  wedge  to  split 
the  timber. 

Drive  the  ring  home  either  with  sledge  and  flatter,  or  by 
upending  the  timber  upon  a  smooth  solid 
surface  and  using  the  timber  as  a  ram  for 
driving  home  the  ring.  As  soon  as  the 
rings  have  been  driven,  drive  the  gudgeons ; 
then  place  the  roll  between  two  surfaces 
which  will  catch  the  two  gudgeons,  and 
revolve  the  roll  to  see  if  the  gudgeons 
are  central. 

Frequently  it  will  be  found  that  one  or 
more  of  them  has  followed  a  crooked  hole 
and  will  not  run  true  enough  to  finish 
up  when  it  is  to  be  turned.  To  cure  this, 
rest  the  gudgeon  on  a  solid  corner,  close 

to  the  end  of  the  roll-timber.  Turn  the  gudgeon  so  that  the 
eccentricty  of  the  end  of  the  gudgeon  is  uppermost,  and  have  a 
man  strike  with  a  sledge  on  the  end  of  the  gudgeon  which  is 
easily  bent  in  this  manner  until  it  runs  approximately  true  and 
will  "clean-up"  when  placed  in  the  lathe. 

FINISHING  THE  ROLLS. 

Having  been  ringed  and  gudgeoned  as  above,  the  rolls  are 
ready  for  the  lathe,  and  the  gudgeons  should  be  centered  in  the 
usual  manner,  squared  up,  and  then  the  roll  should  be  turned  to 
size  before  the  gudgeons  are  shouldered  down.  The  filing  and 
polishing  of  small  journals  is  not  apt  to  be  improved  by  the  fast 
revolving  of  a  mass  of  ragged  wood  on  the  roll ;  therefore  clean 
up  the  roll  and  then  turn  the  shoulders  in  the  gudgeons  and  a 
better  job  will  be  obtained. 

LAGGING  PULLEYS  TO  INCREASE  THEIR  DIAMETER. 

Changes  in  a  mill  frequently  require  a  pulley  to  be  increased 
a  couple  of  inches  in  diameter  in  order  to  increase  the  output  of  a 
machine  or  a  group  of  machines.  It  frequently  happens  that  a 


364  MILLWRIGHTING 

pulley  can  be  lagged  a  couple  of  inches — or  even  five  or  six 
inches — quicker  and  cheaper  than  it  can  be  replaced  by  another 
pulley.  This  is  particularly  the  case  with  wooden  pulleys,  but  even 
cast-iron  or  steel-rim  pulleys  may  be  lagged  to  advantage  by 
drilling  a  couple  of  rows  of  holes  around  the  rim  circumference. 
The  drilling  may  be  done  in  the  most  convenient  manner  pos- 
sible, and  even  a  breast  drill-stock  and  a  5/16-inch  drill  will  give 
a  good  account  of  itself  if  the  workman  cannot  get  hold  of  an 
electric  drill  which  attaches  to  any  electric  light  socket.  That 
instrument  is  the  one  to  drill  small  holes  with,  but  drill  them  any 
way,  only  get  them  through.  If  nothing  better  is  at  hand,  and  a 
wrought  steel  rim  must  be  drilled  with  a  carpenter's  brace  and  a 
bit-stock  drill,  then  procure  a  center  punch  and  grind  it  to  a 
sharper  bevel  than  usual.  Place  a  solid  piece  of  metal  under 
the  pulley-rim  and  obtain  a  solid  bearing  where  the  hole  is  to  be 
made.  Then  drive  in  the  center  punch  as  far  as  it  will  go,  put 
in  the  drill  and  give  it  a  few  turns.  It  will  cut  very  quickly  where 
the  punch  has  driven  the  center.  Alternate  with  punch  and  drill 
and  a  hole  will  be  made  before  you  are  aware  of  it.  Many  a  tough 
hole  can  be  "worried"  through  in  this  manner. 

MAKING  LAG  PATTERNS. 

To  lay  out  a  lag  pattern,  procure  a  bit  of  thin  stuff,  14  to  % 
inch  thick  (a  shingle  lias  done  duty  many  a  time)  and  tack  it 
to  floor  or  bench  as  shown  at  a,  Fig.  138.  With  a  trammel  or  a 
big  pair  of  compasses  draw  a  circle  c,  about  the  center  b,  with  a 
diameter  equal  to  that  of  the  pulley  to  be  lagged.  Make  the  cir- 
cle cut  on  to  the  board  about  2%  inches,  then  draw  the  dotted 
line  b  d,  making  it  dotted  from  center  to  circumference  and  draw- 
ing a  full  line  from  circumference  across  the  board  to  d.  Next, 
saw  off  the  board  at  c,  two  or  three  inches  from  line  d,  and  the 
pattern  is  complete,  though  the  end  of  the  pattern  at  d  may  be 
cut  off  leaving  the  distance  from  that  end  of  the  pattern  to  the  cir- 
cumference line  a  little  more  than  the  thickness  of  the  lag  which 
is  to  be  made. 

The  completed  pattern  is  shown  at  f.  It  is  to  be  used  as  a  set 
square  for  testing  the  dressing  of  the  lags,  one  of  which  is  shown 
in  section  at  g,  and  it  is  to  be  planed  or  machined  until  it  fits  the 
pattern  /  on  three  sides.  A  completed  lag  is  shown  in  section  at  h. 


SOME  SHOP  WORK 


365 


n   m 


Nearly  all  the  work  on  a  set  of  lags  may  be  done  on  a  circu- 
lar saw.  The  curve  i  j  k  may  be  worked  out  by  running  the  lags 
at  nearly  a  right  angle  across  a  large  circular  saw,  the  teeth  of 
which  project  through  the  saw  table  the  depth  of  the  cut  at  ;'.  A 
good  deal  of  labor,  and  lumber  also,  may  be  saved  by  a  little  study 
of  the  large  section  of  a  lag  shown  at  i  k  m.  It  will  be  noted 
that  there  is  no  use  in  dressing  down  g  until  pattern  /  fits  all  the 
way  across,  for  at  i  k  is  shown  all  that  can  be  used  of  the  curve, 
the  edges  k  I  being  cut  off  when  the  lag  is  jointed  on  the  edge,  the 


FIG.   138.— LAYING  OUT  A  LAG  PATTERN. 

strip  k  I  m  going  to  waste ;  hence  it  is  not  necessary  to  fit  the  dis- 
tance k  I. 

In  the  same  manner,  another  saving  of  time  and  stock  may  be 
made  by  beveling  only  from  k  to  m,  leaving  m  n  to  be  removed 
when  the  pulley  is  turned.  By  a  careful  use  of  the  circular  saw, 
lags  may  be  gotten  out  so  smoothly  and  so  true  to  pattern  that  only 
a  touch  of  the  hand  plane  will  be  needed  to  make  a  fine  fit.  It 
makes  no  difference  how  wide  or  how  narrow  a  lag  may  be  across 
the  face  i  k,  for  the  edges  are  all  radial  when  laid  out  by  pattern 
/ ;  hence  any  width  of  stock  may  be  used  which  will  give  the  neces- 
sary thickness  of  lag. 


366 


MILLWRIGHTING 


BUILDING  WOOD  PULLEYS  ON  HUBS  AND  FLANGES. 

It  was  once  almost  an  invariable  rule  that  when  a  pulley  was 
needed,  a  hub  and  flange  would  be  cast  and  bored  to  fit  the  shaft, 
key-seated  at  the  machine  shop  and  then  sent  out  to  the  millwright 
for  the  erection  of  a  pulley  of  the  required  diameter  and  face,  the 
hub  and  flange  being  used  as  a  foundation.  To  do  this,  the  pat- 
tern shown  by  the  shaded  segment  o  p  would  be  carefully  worked 
out  and  sent  to  the  mill  where  lumber  enough  was  jigged  or  band- 
sawn  into  segments  to  build  up  the  necessary  number  of  circles 
to  give  the  desired  width  of  pulley  face. 

One  of  the  old-time  flanges  is  represented  at  A,  while  a  pulley 


FIG.    139.— BUILDING  A  WOOD   PULLEY  ON  A  FLANGE. 

in  process  of  construction  is  shown  at  B,  Fig.  139.  Circles  or 
disks  of  %  or  1  inch  dressed  lumber  are  first  gotten  out  to  amount 
to  a  little  less  than  one-third  the  width  of  pulley  face.  These  cir- 
cles are  fitted  to  each  other,  glued  and  nailed  as  shown  at  a  and 
b,  sketch  B.  When  the  requisite  thickness  of  web,  as  it  is  called, 
has  been  built  up,  the  flange  is  bolted  to  the  wooden  web,  and 
usually  another  thickness  of  stuff  is  broken  around  the  outside 
of  the  flange,  thus  giving  more  bearing  of  the  wood  against  the 
iron. 

As  soon  as  the  web  has  been  completed,  the  segments  c  are 
fitted  in  place,  nailed  and  glued,  until  the   necessary  width  of 


.SOME  SHOP  WORK  367 

face  has  been  worked  up.  Then  "set"  every  nail,  mount  the  pulley 
on  a  shaft  and  turn  the  face,  the  edges  of  the  face,  and  as  much 
of  the  remainder  as  is  necessary  to  make  the  needed  finish. 
Beware  of  driving  nails  close  to  the  face  of  the  pulley,  or  you  will 
surely  hit  some  of  them  while  doing  the  turning  act.  An  excel- 
lent tool  for  roughly  turning  a  large  pulley  is  the  tang  of  a  large 
file,  ground  to  a  flat  chisel-like  point  not  over  %  inch  wide.  This 
will  cut  off  more  wood  than  a  dozen  chisels  and  it  will  not  require 
one-tenth  the  amount  of  grinding  that  the  chisels  will  call  for. 

PREPARING  AND  USING  GLUE. 

When  gluing  the  circles  and  segments  of  the  pulley,  the  closer 
together  the  wood  is  brought,  the  stronger  will  be  the  joint.  If 
two  pieces  of  wood  be  fitted  together  as  closely  as  possible,  then 
covered  with  a  coating  of  glue  and  squeezed  together  in  a  press, 
the  joint  will  be  a  much  better  one  than  when  the  pieces  are  merely 
laid  together  and  fastened  with  nails  or  screws. 

If  the  pieces  are  heated  before  they  are  placed  together,  or 
while  in  the  press,  the  joint  will  be  still  better.  Therefore,  to 
make  the  best  possible  glue  joint,  the  pieces  should  be  heated, 
fitted  and  pressed  as  closely  together  as  possible  during  the  setting 
of  the  glue.  It  is,  then,  important  that  the  surfaces  be  evenly 
coated  with  glue,  and  as  thin  glue  spreads  easier  and  more  evenly 
than  thick,  the  former  should  always  be  used.  Thin  glue  is  much 
more  economical  as  less  of  it  is  used,  but  the  joints  must  be  good 
and  the  pieces  placed  closely  in  contact  when  thin  glue  is  to  be  used. 
The  botch  workman  can  make  a  little  better  job  with  thick  glue 
than  with  thin — a  little  better  looking  job,  at  least,  but  it  will 
not  be  as  strong  a  piece  of  work  as  if  the  parts  had  been  properly 
fitted  together. 

HOT  AND  COLD  GLUE. 

There  is  no  very  good  way  of  testing  glue  except  by  its  physi- 
cal appearance.  Glue  which  has  an  even  color  and  which  breaks 
evenly  with  a  tough,  firm  yet  clean  "snap"  may  be  taken  as  a  good 
glue,  no  matter  what  its  color  may  be.  It  is  well,  •  however,  to 
avoid  glues  which  are  too  dark,  as  they  may  contain  quantities 
of  foreign  matter  which  should  have  been  removed  by  better  fil- 
tering during  the  process  of  making  the  glue.  Usually,  the  whiter 
the  glue,  the  higher  the  price  at  which  it  is  sold. 


368  MILL  WEIGHTING 

To  prepare  hot  glue  for  use,  place  the  required  quantity  of 
dry  glue  in  a  vessel  and  cover  with  cold  water.  It  makes  no 
difference  how  great  a  quantity  of  water  is  used  for  the  glue  will 
only  absorb  a  certain  amount.  It  is  best  to  place  the  glue  in  the 
water  at  night;  then  the  next  morning  pour  off  all  the  water 
except  what  has  been  absorbed  by  the  glue,  which  should  then 
be  placed  in  the  regular  double  glue  pot  and  melted.  Dry  glue 
will  absorb  just  the  amount  of  cold  water  that  is  necessary  for 
melting  the  glue  with  heat — quite  a  handy  arrangement. 

Glue  will  not  dissolve  in  cold  water,  though  it  will  soften,  as 
shown  above.  To  prepare  a  glue  which  will  not  turn  into  jelly 
after  it  has  been  heated  and  allowed  to  become  cold  again,  add 
some  acetic  acid,  and  the  property  of  gelatizing  when  cold 
becomes  lost.  Nitric  acid  may  be  used  instead  of  acetic,  if  desired, 
so  may  hydrochloric  (muriatic)  acid.  None  of  the  adhesive 
strength  is  lost,  and  glue  thus  prepared,  which  is  sold  as  "cold" 
glue,  "prepared"  glue,  etc.,  may  be  used  without  heating  if 
necessary,  but  better  results  can  be  obtained  by  heating  the  glue, 
likewise  the  articles  to  be  glued,  the  same  as  when  using  ordi- 
nary, or  "hot"  glue. 

Glue  joints  may  be  made  waterproof  by  adding  a  little  bichro- 
mate of  potash  to  the  glue  before  using,  and  then  exposing  the 
glued  and  dried  joint  to  the  action  of  sunlight,  which  acts  upon 
the  bichromate  and  renders  the  glue  insoluble  in  water.  But  it 
won't  work  without  sunlight. 

BITS  AND  BORING. 

Compared  with  forty  years  ago,  the  millwright  of  today  has 
a  selection  of  bits  and  wood  boring  tools  which  would  be 
regarded  as  little  short  of  marvelous  could  they  have  been  placed 
in  the  hands  of  the  millwright  of  four  decades  ago.  The  auger 
bit,  the  center  bit  and  the  "spoon"  bit  constituted  the  woodboring 
tools  at  that  time,  and  when  the  so-called  "patent"  auger  was 
added,  it  seemed  to  the  millwright  that  nothing  further  could  be 
desired  in  the  line  of  boring  tools.  But  now  the  millwright  can 
select  a  bit,  or  a  whole  set  of  bits,  ranging  by  thirty-seconds  of 
an  inch  from  V,  to  iy4  inches,  and  increasing  by  larger  fractions 
to  3  or  even  4  inches  in  diameter.  These  bits  may  be  procured 
in  infinite  variety,  each  designed  for  some  particular  operation, 
and  almost  perfection  for  the  purpose  for  which  it  was  designed. 


SOME  SHOP  WORK 


369 


There  are  the  common  auger  bits  with  a  lip  or  spur  above  the 
horizontal  cutting  lip,  and  a  spur  below  that  lip.  These  bits  cut 
well  and  smoothly  in  soft  wood,  but  they  go  awful  hard  in  the 
more  dense  woods  and  are  rendered  almost  useless  when  run 
against  a  nail.  A  bit  of  this  kind  is  shown  at  B,  Fig.  140,  a  lip  b 


FIG.    140.— BITS   AND    BORING. 

being  found  at  opposite  points,  and  a  spur  a  being  placed  as 
shown.  When  the  bit  was  new,  a  similar  spur  was  to  be  found  at 
c,  but  for  repair  work,  for  boring  hard  wood,  and  for  boring  end- 
wood,  the  spurs  are  filed  off  as  shown  at  c,  leaving  lips  b  and  c 
to  do  all  the  work  of  cutting  the  edge  of  the  chip.  After  a  bit  has 


370  MILLWRIGHTING 

been  used  for  a  long  time,  the  lips  become  very  small,  or  are 
entirely  removed  as  shown  at  C.  A  bit  of  this  kind  is  utterly 
worthless  for  boring-  side-wood.  It  is,  however,  a  first-class  tool 
for  boring  into  the  end  of  a  piece  of  hard  wood  and  should  be  kept 
for  that  work.  Remove  the  worm  from  this  bit  and  it  becomes  a 
most  excellent  tool  for  machine-boring  and  end-wood — but  it  is 
not  worth  a  "continental"  for  side  work,  either  in  hard  or  in  soft 
woods. 

Bit  A  shows  a  type  of  tool  with  no  lip,  the  underneath  spur 
doing  all  the  work  of  edge-cutting  the  chip.  This  is  a  fine  cutting 
bit  but  it  requires  a  lot  of  power  in  hard  wood,  and  soon  becomes 
like  C  when  abused  by  running  against  nails.  This  is  a  good 
bench  tool  and  it  will  cut  smooth  holes,  but  the  bit  should  not  be 
put  into  general  mill  repair  work. 

BITS  FOR  REPAIR  WORK. 

Bit  B,  without  the  spurs  a,  is  the  tool  for  repair  and  general 
mill  work,  and  is  the  best  all-around  bit  made.  Tool  D,  how- 
ever is  the  mill  bit,  and  should  be  in  the  chest  of  every  millwright. 
This  is  a  single  lip  bit  and  it  is  the  one  known  to  the  old  school 
millwrights  as  the  "patent"  bit.  It  is  the  type  almost  universally 
used  for  ship  and  bridge  work  and  it  will  stand  more  hard  work 
and  abuse  than  any  other  bit  made. 

It  has  a  single  lip,  no  spur,  and  the  chip-removing  spiral  is 
made  of  very  heavy  half-round  steel,  as  shown  by  the  section  s. 
This  tool  is  heavy  enough  to  stand  straightening  with  a  mallet 
when  bent,  and  it  can  be  welded  to  shanks  of  any  length,  or  used 
with  extensions  or  ship  handles,  as  desired,  without  being  spoiled 
or  even  seriously  damaged  by  misuse  and  abuse. 

FANCY  AND  BENCH  BITS. 

For  fine  bench  work,  and  for  pattern-making,  the  types  of 
bits  shown  by  sketch  E,  F  and  G  are  very  desirable.  Bit  E  is  a 
most  excellent  tool  with  double  cutting  lips  and  single  chip  spiral. 
This  bit  has  the  bottom  spur,  but  somehow  it  still  seems  to  cut 
end- wood  very  well  and  it  does  not  go  so  very  hard  in  oak  or 
other  hard  woods.  Bit  P  is  the  easiest  cutting  bit  on  the  market, 
and  this  bit  works  equally  well  against  end  or  side-grain  and 
it  has  neither  lip  or  spur  for  cutting  the  edge  of  the  chip.  Instead 


SOME  SHOP  WORK  371 

of  either  the  above  devices,  the  edges  of  bit  are  turned  up  so  that 
there  is  no  need  of  either  device,  for  there  is  no  corner  in  the 
hole  and  no  edge  to  be  cut.  The  hole  is  round-bottomed  and  the 
chips  are  feather-edge  affairs.  But  when  these  bits  run  against 
nails  it  is  all  off,  and  a  new  bit  is  the  only  cure  for  nail  cutting. 
They  will  not  be  used  for  repair  work. 

A  bit  which  will  bore  a  hole  with  a  smooth  flat  bottom  is 
shown  at  G.  This  is  a  very  handy  tool  when  making  patterns, 
and  it  can  be  started  on  a  beveled  surface,  in  a  V-shaped  corner, 
or  almost  anywhere  that  a  common  bit  would  give  trouble  in  start- 
ing to  work.  A  set  of  these  bits  is  a  most  convenient  possession 
for  the  millwright  who  prides  himself  upon  the  extent  of  his  kit 
of  tools.  They  are,  also,  most  excellent  machine  bits  for  power 
use. 

REAMING  AND  ENLARGING  HOLES. 

For  this  class  of  work,  the  bit  shown  by  D,  Fig.  140,  is  about 
the  best  "store"  bit  the  millwright  can  obtain.  The  spoon  bit, 
or  "pod  auger,"  shown  by  Fig.  135,  is  a  most  excellent  device  for 
enlarging  a  hole  already  made.  But  if  it  be  desired  to  bore  a  hole 
over  or  around  a  smaller  hole  without  following  the  first  made 
hole,  then  bit  D  will  do  the  business,  likewise  will  bit  G,  pro- 
vided the  hole  be  a  shallow  one.  Bit  G  will  not  remove  chips ; 
hence  its  use  in  reaming  or  enlarging  holes  is  limited  to  holes  not 
very  deep.  With  the  spur  removed  from  bit  D,  it  will  bore 
through,  across,  or  along  another  hole  and  will  continue  to  bore 
straight  in  the  direction  in  which  the  bit  was  started. 


BORING  LONG  HOLES. 

It  is  evident  that  holes  of  any  depth,  up  to  the  length  of  the 
bit  stem  or  extension,  may  be  bored  if  care  be  taken  to  remove  the 
chips  before  they  clog  around  the  stem.  In  boring  holes  four  or 
six  feet  deep  with  10  inches  of  chip-spiral,  it  is  evident  that  only 
a  certain  number  of  chips  can  be  cut  off  before  the  spiral  will 
be  full.  Before  the  spiral  gets  quite  out  of  sight,  count  the  num- 
ber of  turns  required  to  fill  it.  Suppose  it  is  found  that  25  turns 
of  the  bit  fills  the  chip  removing  spiral.  Bore  only  20  turns  of 
the  bit,  then  remove  it  and  bore  20  turns  more.  In  this  manner, 


372  MILLWRIGHTING 

a  bit  will  never  become  clogged  in  the  hole,  something  which  fre- 
qeuntly  happens  when  the  chips  are  not  "counted  out." 

BORING  THROUGH  KNOTS  AND  SPIKES. 

In  mill  repair  work,  a  man  cannot  pick  the  place  to  bore  a 
hole,  but  he  must  work  to  the  mark,  no  matter  if  a  broken  spike, 
a  fierce  knot  or  a  rusted-off  bolt  already  occupies  the  place  where 
a  hole  is  needed.  It  is  in  such  cases  that  the  skill  of  the  millwright 
becomes  manifest.  He  will  dig  in  with  a  cold-chisel  and  cut  off 
the  offending  bit  of  metal,  or  he  will,  perhaps,  be  able  to  drive  in 
a  drift  and  force  the  metal  to  one  side,  after  which  the  hole  may 
be  continued. 

Sometimes  it  is  necessary  to  weld  an  extension  to  the  shank 
of  a  twist  drill  and  remove  the  bit  of  hard  metal  in  that  manner. 
To  guard  against  trouble  in  this  direction,  especially  in  small 
shallow  holes,  the  up-to-date  millwright  adds  to  his  kit  a  set  of 
twist  drill  bits.  These  most  excellent  tools  are  like  cigars,  only 
"more  so" — they  don't  give  a  continental  who  uses  them,  or  what 
they  are  used  on,  and  they  will  go  right  through  wood,  steel 
or  knots. 

SMALL  BITS. 

For  boring  holes  less  than  14  inch  in  diameter,  there  is  a  pro- 
fusion of  styles  to  select  from,  and  the  millwright  will  do  well 
to  select  a  set  of  gimlet-pointed  spoon  bits  and  back  them  up  with 
the  twist  drill  bits  mentioned  in  the  preceding  paragraph.  The 
writer  remembers  the  time  when  the  "spoon"  bit  and  the  "capped 
spoon  bit"  were  about  the  only  obtainable  bits  for  making  small 
holes.  Then,  it  was  frequently  necessary  to  forge  a  bit-shank 
and  make  a  half-round  attachment  to  the  shank,  which  attach- 
ment, after  being  ground  or  filed  to  size,  and  made  very  smooth 
and  sharp,  would  be  twisted  into  a  shape  approximating  a  twist 
drill  and  a  gimlet.  The  result  was  usually  a  bit  which  would 
work  extremely  well.  Being  soft,  it  would  not  break,  but  could 
be  straightened  when  necessary.  It  had  to  be  frequently  sharp- 
ened, but  it  was  an  excellent  addition  to  the  stock  of  small  bits. 

To  illustrate  the  scarcity  of  "store  tools"  only  a  few  decades 
ago,  one  instance  may  be  cited :  A  concern  doing  a  good  deal  of 
machine  work  and  millwrighting  procured  a  "set"  of  twist  drills 


SOME  SHOP  WORK  373 

— they  were  just  out  then  and  a  "set"  consisted  of  one  drill  of 
each  size  by  sixteenths  of  an  inch.  For  the  first  year  these  drills 
were  possessed  by  that  shop,  so  great  a  rarity  were  they  consid- 
ered that  the  "set"  of  drills — board  and  all — were  kept  in  the 
office  safe. 

SHARPENING  BITS. 

Usually  the  millwright  will  sharpen  a  bit  with  the  first  file  he 
lays  his  eyes  upon.  Bits  can  be  sharpened  in  this  way,  but  there 
is  a  way  of  doing  it  which  will  secure  a  much  better  job  and 
save  a  good  deal  of  metal  which  is  now  wasted  by  using  a  coarse, 
heavy  file.  There  are  small  files  in  the  market,  each  with  a  small 
projecting  portion  in  place  of  the  usual  tang,  which  serves  as  a 
handle.  Several  of  these  little  files  should  be  procured  and  kept 
for  sharpening  bits  and  for  other  small  work  for  which  regular 
files  are  not  suitable. 

An  assortment  of  half  a  dozen  files  will  enable  a  man  to  take 
care  of  any  bit  which  may  come  along,  but  more  shapes  will  prove 
very  convenient  at  times.  The  author  has  a  collection  of  about 
30  different  sizes  and  shapes,  from  2  to  6  incheo  long.  These 
files  are  kept  in  a  tin  box,  one  end  of  which  is  partitioned  off 
a  couple  of  inches  and  a  bit  of  unslaked  lime  is  at  all  times  kept 
in  the  space  thus  partitioned  off.  In  time,  the  lime  becomes 
powdered  and  sifts  among  the  files.  It  does  no  harm  there,  but 
never  a  bit  of  rust  will  ever  find  its  way  among  those  files  as 
long  as  unslaked  lime  remains  in  the  box.  Lime  will  "gobble" 
every  particle  of  moisture  which  comes  along  in  the  air  A  piece 
of  lime  kept  in  a  tool  chest  will  prevent  the  tools  from  rusting. 

When  sharpening  bits,  make  it  an  invariable  rule  to  do  all  the 
filing  on  that  side  of  the  lips  and  spurs  against  which  the  chips 
pass.  Never  do  any  filing  on  the  surfaces  which  bear  against  the 
sides  or  the  bottom  of  the  hole.  This  makes  it  necessary  to  file 
all  spurs  on  the  inside  and  to  file  all  cutting  lips  on  the  side  next 
to  the  ship  spiral.  Sometimes  it  is  necessary  to  file  the  other  side 
of  a  lip  in  order  to  repair  the  damage  done  by  some  one  who 
knew  no  better  than  to  sharpen  a  bit  on  the  outside.  When  such 
is  the  case,  file  the  surfaces  back  far  enough  to  give  them  clear- 
ance so  the  bevel  or  face  thus  formed  will  touch  the  wood  at  the 
cutting  edge  and  nowhere  else.  When  a  bit  is  so  filed  that  the 


374  MILLWRIGHTING 

heel  of  a  bevel  or  face  touches  the  wood  before  the  cutting  edge  can 
get  to  work,  then  there  is  no  use  of  trying  to  bore  with  that  bit 
until  it  has  been  filed  to  the  proper  clearance. 

REPAIRING  DAMAGED  OR  WORN  BITS. 

It  often  happens  that  bits  are  put  out  of  business  by  being 
run  against  nails  or  other  pieces  of  metal.  The  expert  mechanic 
can  usually  tell  the  first  time  a  bit  touches  metal,  but  sometimes 
when  working  in  a  deep  hole,  there  is  so  much  friction  that  the 
bit  turns  very  hard  and  the  slight  "rub''  of  nail  or  spike  is  not 
noticed  and  the  bit  hits  a  second  time.  Little  damage  can  be  done 
when  a  bit  hits  but  once  or  twice,  but  when  the  unskilful  man 
grinds  a  bit  against  steel  time  after  time,  then  a  good  deal  must 
be  done  to  the  cutting  lip  before  that  bit  can  make  a  hole  again 
with  any  comfort  to  the  user. 

When  a  lip  or  a  spur  has  been  ground  off  to  a  dull  corner,  the 
only  thing  is  to  file  away  metal  from  the  inside  of  that  lip  or  that 
spur  until  a  new  cutting  edge  is  formed.  The  filing  must  be  car- 
ried back  on  a  good  long  bevel  so  as  to  maintain  the  same  angle 
of  cutting  edge  which  existed  before  repairs  were  made.  There 
is  a  limit  to  the  filing  which  can  be  done  in  this  manner,  and  that 
limit  is  the  amount  of  metal  in  spur  or  lip.  The  limit  has  been 
reached  in  bit  C,  Fig.  140,  for  the  lip  has  been  all  filed  away.  In 
bit  E,  the  limit  is  at  c.  When  the  lip  has  been  filed  back  to  that 
point,  the  spur  will  have  been  all  filed  away  and  the  bit  will  be  in 
the  same  condition  as  bit  C. 

EXPANDING  A  BIT. 

Bits  are  sometimes  ground  against  steel  or  grit  until  the  diame- 
ter at  b  c,  sketch  B,  Fig.  140,  becomes  less  than  diameter  d  c. 
When  this  happens,  the  fact  becomes  apparent  at  once  by  the 
power  required  to  turn  the  bit  in  the  hole.  For  the  first  inch,  the 
bit  may  cut  all  right,  but  as  soon  as  the  larger  portion  of  the  spiral 
gets  into  the  hole  made  by  the  worn  down  lip,  then  trouble  begins 
and  the  bit  runs  very  hard. 

This  defect  is  quite  easy  to  remedy,  and  to  effect  a  cure  it 
is  only  necessary  to  stretch  that  portion  of  the  bit  between  b 
and  c.  This  may  be  quickly  done  by  placing  the  bit  in  such  a 
position  that  the  chip  side  of  the  lip  will  bear  firmly  and  solid  upon 


SOME  SHOP  WORK  375 

some  heavy  mass  of  metal.  The  corner  of  an  anvil  or  the  jaw 
of  a  vise  will  answer  very  well.  Sometimes  the  point  of  a  crow- 
bar proves  to  be  just  the  thing  when  the  bar  is  screwed  tightly 
into  the  vise  with  only  three  or  four  inches  of  the  point  projecting 
above  the  vise  jaws. 

But  with  the  bit  thus  placed  and  solidly  held  in  place,  with  a 
pene  hammer,  or  with  a  thick  punch  and  any  old  hammer,  place 
many  blows  along  the  cutting  edge  between  b  and  c.  The  object 
is  to  stretch  this  edge,  thus  increasing  the  distance  between  b  and 
c  until  it  is  a  little  greater  than  the  diameter  d  e. 

It  is  quite  easy  to  thus  increase  the  diameter,  and  the  swaging 
may  not  be  confined  to  the  cutting  edge  alone.  Just  back  of  the 
edge  there  is  more  metal  than  at  the  edge  itself,  and  swaging 
therei  stretches  the  edge  itself,  where  there  is  no  metal  to  swage. 
Bit  D  is  very  easy  to  fix  so  it  will  cut  a  larger  hole.  All  that  is 
necessary  is  to  grind  a  dull  cold-chisel  to  the  rounded  shape  of  a 
boiler  calking  tool;  then,  with  the  bit  laid  in  some  solid  metal 
corner,  place  the  rounded  tool  along  the  line  t  t  and  strike  a  few 
blows  with  a  hammer.  The  result  will  be  that  the  cutting  lip  is 
thrown  outward  beyond  the  line  of  the  chip-spiral  and  thus  cuts 
itself  free. 

Whenever  a  bit  has  to  be  straightened,  never  do  it  with  a  ham- 
mer. Just  lay  the  bit  on  wood — end-wood  is  the  best — then  strike 
where  necessary  with  a  rather  light  hardwood  mallet.  This  will 
bend  the  bit  without  stretching  or  swaging  it  as  might  be  the  case 
if  the  bit  were  laid  upon  an  anvil  and  struck  with  a  hammer. 


CHAPTER  XX. 

WATER-WHEEL  SETTING. 

Water-wheel  setting  may  soon  become  a  lost  art  as  far  as  its 
practise  by  the  millwright  is  concerned.  The  wooden  flume,  the 
framed  penstock  and  the  wooden  wheel  case  are  things  of  the  past 
and  are  seldom  seen,  much  less  constructed,  nowadays.  The 
boiler  maker  and  the  concrete  worker  does  about  all  the  water- 
wheel  setting  now,  and  it  is  done  to  stay.  The  old-time  wooden 
construction  used  to  last  about  seven  years  before  it  came  to 
repair,  and  at  ten  years  the  whole  thing  had  to  be  replaced  with 
new  material. 

FLUME  CONSTRUCTION. 

It  was  the  intention,  when  this  book  was  planned,  to  give  a 
description  of  advanced  methods  of  flume  construction,  to  discuss 
the  methods  of  framing  flume  timbers,  of  planking  and  of  water- 
proof woodwork  in  general,  but  in  casting  about  for  the  latest 
examples  of  wooden  flume  construction,  it  must  be  admitted  that 
even  a  single  example  worthy  of  description  cannot  be  found. 
The  open  flume,  the  decked  flume  and  the  penstock  have  all  been 
replaced  by  steel  and  cement  so  thoroughly  that  wooden  flume 
making  is  an  obsolete  branch  of  millwrighting. 

DECK  FLUME  FRAMING. 

It  was  once  the  hight  of  the  millwright's  ambition  to  be  able 
to  frame  and  erect  a  deck  flume  in  which  water  could  be  con- 
fined under  10  to  40  feet  head,  and  not  a  drop  of  water  found 
leaking  from  the  flume.  But  the  concrete  wall  reinforced  with 
a  little  steel  has  taken  the  place  of  the  high  flume,  the  cast-iron 
and  steel  wheel  case  has  replaced  the  wooden  deck. 

TURBINE-WHEEL  SETTING. 

When  the  setting  of  a  turbine  wheel  used  to  be  the  labor  of 
weeks  for  a  considerable  force  of  highly  skilled  mechanics,  now 

376 


WATER-WHEEL  SETTING  377 

it  is  only  the  work  of  a  single  day  for  a  foreman,  a  gang  of  labor- 
ers and  a  couple  of  boiler  makers — the  latter  to  drive  the  rivets 
which  connect  the  wheel  case  with  the  steel  penstock  and  draft- 
tube. 

The  foundation  for  the  wheel  case  was  made  when  the  founda- 
tions of  the  mill  were  constructed,  and  all  that  can  be  seen  of 
it  are  several  anchor  bolts  projecting  from  a  smooth  concrete 
floor.  So  exact  has  been  the  engineering  work  with  transit  and 
station-rod,  that  after  the  wheel  case  has  been  dropped  in  place, 
it  needs  nothing  except  being  twisted  around  a  little  to  coincide 
with  the  shaft  and  building  lines  and  perhaps  leveled  up  a  bit 
with  some  brimstone  and  a  steel  wedge  or  two. 

Modern  turbine  wheels  are  so  entirely  self-contained,  even  the 
larger  sizes,  that  "wheel  setting/'  as  known  to  the  old-school  mill- 
wright, is  absolutely  a  thing  of  the  past.  Nowadays,  the  mill- 
wright sets  the  wheel  case,  connects  the  gate  hand  wheel  and 
puts  on  the  belt.  He  may,  perhaps,  never  even  see  the  water 
wheel  itself,  unless,  as  a  matter  of  precaution,  as  noted  under  the 
head  of  engine  setting  (chapter  XVII,  page  331),  he  takes  down 
the  wheel  and  looks  to  the  manner  of  workmanship  which  has 
been  sold  to  his  employers  with  the  water  wheel. 

GEAR  OR  BELT  TRANSMISSION. 

It  is  safe  to  state  that  not  more  than  once  in  a  lifetime  will 
the  millwright  be  called  upon  to  set  up  a  geared  power  transmis- 
sion from  water  wheel  to  line  shaft.  The  belt  or  the  rope  drive  is 
the  method,  unless  a  direct-connected  electric  generator  stands 
beside  the  water  wheel  and  displaces  both  belts  and  ropes.  The 
direct  flexible  connection  between  water  wheel  and  electric  gener- 
ator is  about  as  near  the  ideal  as  the  millwright  can  get  until  he  is 
able  to  take  electricity  direct  from  the  water  by  means  of  a 
single  machine! 

With  the  gear  transmission  has  gone  the  vertical  water  wheel 
shaft  which  made  toothed  bevel  gearing  a  necessary  link  in  power 
transmission.  When  the  steel  wheel  case  came  into  existence,  the 
wheel  shaft  immediately  assumed  a  horizontal  position,  thus  mak- 
ing it  possible  to  use  plain  belting  to  advantage  when  distant  shaft- 
ing had  to  be  driven.  In  many  instances,  water  wheels  are 
direct-connected  to  the  main  line  of  shafting. 


378  MILLWRiGHTING 

PENSTOCK  AND  DRAFT-TUBE  WHEEL  SETTING. 

It  is  no  longer  necessary  to  place  the  water  wheel  in  a  bot- 
tomless pit,  or  a  pretty  close  approximation  to  one — the  ancient 
"wheel-pit."  By  the  development  of  the  draft  tube,  a  wheel  may 
be  placed  at  any  level  above  the  tail  water  inside  of  30  feet  and 
as  good  results  obtained  as  when  all  the  water-head  was  above  the 
wheel.  Gear  case,  penstock  and  draft  tube  can  all  be  made  per- 
fectly water  and  air  tight  so  the  wheel  can  be  located  at  any  level 
inside  which  air  pressure  will  not  be  exceeded  by  the  water 
pressure. 

To  all  intents  and  purposes,  the  modern  water-wheel  setting  is 
merely  a  steel  penstock  running  from  the  source  of  water  supply 
to  the  lowest  point  available  on  the  discharge  side  of  the  wheel, 
with  the  wheel  case  cut  into  the  penstock  at  some  convenient  point 
not  more  than  30  feet  above  low  water  in  the  tail  race.  All  the 
open  flume  that  is  necessary  is  what  local  conditions  demand  to 
connect  the  river  with  the  penstock.  All  the  flume  and  "wheel 
pit"  construction  necessary  in  the  mill  is  that  demanded  by 
local  conditions  for  supporting  the  water  wheel  and  the  other 
machinery. 

Reduced  to  its  lowest  terms,  modern  water-wheel  setting  is 
nothing  more  than  the  construction  of  a  pipe  line  of  the  necessary 
diameter  to  supply  the  wheels,  the  line  to  be  continuous  between 
head  and  tail  water,  the  cutting  in  of  one  or  more  water  wheels 
at  some  convenient  point  along  the  pipe  (penstock)  line  not  more 
than  30  feet  above  tail  water. 

THEN  AND  Now. 

To  the  old-school  millwright,  the  wheel-pit  was  a  perpetual 
nightmare — a  continuous  performance  pit  in  which  he  (the  mill- 
wright) might  be  called  at  any  minute,  day  or  night,  to  "do  a 
turn"  in  water  to  his  waist  as  he  wrestled  with  rusty  nuts  and 
bolts  in  the  attempt  to  put  in  a  new  water-wheel  step,  three  feet 
under  water. 

With  the  vertical  shaft  type  of  water  wheel,  it  was  necessary  to 
provide  means  for  holding  up  the  wheel  together  with  a  ton  or 
two  of  shaft  and  gears  as  well.  This  heavy  weight  was  usually 
carried  upon  a  conical  "step"  placed  in  the  end  of  the  shaft  below 
the  water  wheel. 


WATER-WHEEL  SETTING  379 

As  long  as  the  step  was  new,  and  did  not  fit  very  well,  water 
could  get  between  the  shaft  and  the  wood  and  carry  away  the 
heat  as  fast  as  generated  by  friction  between  the  wooden  step 
and  the  end  of  the  wheel  shaft..  But  after  the  step  had  become 
worn  very  smooth,  and  fitted  very  closely  into  the  conical  cavity 
in  the  end  of  the  wheel  shaft,  then  water  would  be  unable  to  get 
into  the  bearing,  heat  would  soon  char  the  wood,  the  charcoal 
thus  formed  would  easily  crumble  under  the  load  of  shaft  and 
water  wheel,  and  very  soon  that  step  would  "go  down"  and  the 
wheel  would  strike  the  bottom  of  the  case,  or  the  gears  on  top  of 
tne  shaft  would  fall  out  of  mesh,  perhaps  stripping  a  gear  or 
two  during  the  operation. 

Eventually,  the  millwright  learned  how  to  prevent  the  burning 
out  of  water-wheel  steps  by  boring  a  vertical  hole  through  the 
center  of  the  wooden  step  and  attaching  a  water  pipe  thereto.  A 
force  pump  conveniently  located  in  the  mill  forced  a  stream  of 
water  through  the  step  at  all  times  when  the  water  wheel  was  run- 
ning. The  stream  of  water  served  two  purposes.  It  not  only 
lubricated  the  metal-wood  combination  of  bearing  surfaces,  but  it 
also  carried  away  the  heat  generated  by  friction  in  the  step  bear- 
ing. Thus,  the  matter  of  step  burning-out  was  forever  settled 
by  the  stream  of  water  business.  Occasionally,  the  pump  got  out 
of  order  through  lack  of  attention,  and  a  step  would  go  down, 
but  that  happened  very  rarely  and  the  water-lubricated  wheel-step 
was  a  pretty  safe  proposition. 

But  the  steel  wheel  case  fixed  forever  the  matter  of  conical 
wooden  water-wheel  steps,  by  abolishing  the  step  altogether.  With 
the  horizontal  wheel  and  shaft,  a  pair  of  bearings  are  used,  one  on 
either  side  of  the  wheel  the  same  as  with  any  other  machine,  and 
the  troublesome  water-wheel  step  is  gone  forever — and  with 
it  the  worst  of  the  millwright's  hardest  work. 

WATER  WHEEL  GOVERNORS. 

The  hardest  task  the  millwright  will  have  in  connection  with 
water  wheels  is  to  make  the  governor  work  in  a  manner  which 
will  govern  the  speed  of  the  wheel  within  the  required  percentage 
of  regulation.  There  has  not  yet  been  perfected  a  water-wheel 
governor  which  will  keep  the  speed  within  2i/>  per  cent,  under  all 
variations  of  load.  There  is  no  possibility  of  so  doing  for  the 


380  MILLWRIGHTING 

reason  that  a  water  gate,  perhaps  aggregating  an  area  of  opening 
of  anywhere  between  two  and  ten  square  feet,  cannot  be  opened 
or  closed  quick  enough  to  permit  of  the  quick  regulation  of  speed 
within  the  stated  limit. 

Water  cannot  be  handled  with  instantaneous  results  like  those 
obtained  from  steam,  and  with  the  enormous  quantity  of  water 
in  a  wheel  case  and  penstock  when  the  governor  acts  to  check  the 
flow  of  water,  there  is  sure  to  be  a  considerable  increase  of  pres- 
sure due  to  the  partial  closing  of  the  gate  which  sets  up  a  sort 
of  "water-hammer"  action  in  the  penstock — sufficient  pressure,  in 
fact,  to  burst  the  penstock  should  it  be  of  considerable  length* 
and  no  vent  or  safety  valve  be  provided. 

It  is  for  the  purpose  of  relieving  the  "momentum  pressure" 
which  is  caused  by  the  more  or  less  sudden  closing  of  a  gate  that 
the  relief  vent  is  always  attached  to  long  penstocks.  When  the 
water-wheel  regulator  partially  closes  the  water  gate  in  response 
to  an  increase  in  speed,  the  very  act  of  partially  closing  the  out- 
let for  the  moving  column  of  water  back  of,  or  above  the  wheel 
gate,  increases  the  pressure  of  that  body  of  water  as  noted  above, 
and  the  increase  of  pressure  increases  the  velocity  of  the  water 
which  does  flow  through  the  gates,  thereby  causing,  in  some 
instances,  an  actual  increase  in  speed  for  a  short  time. 

The  action  is  the  same,  though  in  a  contradirection,  when  the 
speed  falls  and  the  governor  opens  the  gate  to  admit  more  water. 
A  momentary  fall  in  pressure  is  felt  at  the  wheel,  less  water 
flows  through  for  an  instant,  even  though  the  gate  has  been 
opened  wider.  The  water-wheel  governor  is  thus  so  badly  handi- 
capped that  outside  means  must  be  used  for  regulating  the  speed 
of  a  water  wheel  under  suddenly  varying  load  where  close  speed 
variation  is  a  necessity. 

A  friction  device,  controlled  and  actuated  by  the  water-wheel 
governor  and  water  or  steam  pressure,  could  easily  be  made  to 
keep  the  speed  down  during  the  adjustment  of  the  water  column 
in  the  penstock  to  the  changed  area  of  the  opening  at  the  wheel 
gate.  The  governor  could  easily  break  down  the  speed  increase, 
but  the  device  would  be  worthless  for  acceleration  purposes  when 
the  speed  is  to  be  increased. 

The  very  close  regulation  of  a  water  wheel  will  probably  be 
fully  and  satisfactorily  accomplished  only  by  the  use  of  electricity 


WATER-WHEEL  SETTING  381 

through  the  medium  of  a  generator,  a  motor  and  a  storage  bat- 
tery; the  water-wheel  governor  to  be  connected  so  as  to  accom- 
plish the  opening  and  closing  of  the  regulating  gate  by  outside 
energy,  and  at  the  same  time  to  so  actuate  an  electric  controller 
that  the  electric  generator  shall  be  made  to  do  the  work  of  a 
quick-acting  magnetic  brake  when  the  speed  increases.  But  when 
the  speed  decreases,  and  the  governor  opens  the  water  gate,  then 
the  electrical  control  shall  cause  the  motor  to  get  busy  and  increase 
the  speed  of  the  water  wheel  during  the  short  period  of  time 
required  for  the  water-wheel  governor  to  obtain  control  of  the 
speed.  Possibly  a  small  motor-generator  and  a  limited  capacity 
storage  plant  could  be  made  to  do  the  work  with  but  small  loss 
of  power  by  absorption  in  the  electrical  appliances  which  need 
have  but  a  small  percentage  of  capacity,  compared  with  the  water 
power  it  is  to  govern. 

Be  this  as  it  may,  it  is  certain  that  a  man  can  lift  himself  over 
a  shaft  by  his  boot-straps  just  as  easily  as  a  water-wheel  governor 
can  closely  govern  the  speed  of  a  water  wheel  by  throttling  the 
water  supply  of  the  wheel. 

FRAMING  FOR  WHEEL  SHAFTS. 

The  millwright  who  will  keep  water  wheels  in  good  condition 
at  all  times  will  see  to  it  that  their  shafts  are  properly  supported, 
both  as  regards  boxing  and  timbering.  A  water  wheel  is  a  pecu- 
liar beast  at  best,  and  it  cannot  do  its  full  capacity  of  work  when 
binding  in  badly  supported  bearings,  or  when  running  out  of  line 
with  a  kink  or  two  in  the  wheel  shaft  caused  by  worn  out  babbitt 
or  displaced  pillow-blocks. 

The  timbering  or  the  shaft  supports  are  very  important  factors 
in  the  maintenance  of  a  water  wheel.  Unless  the  timbering  is  ade- 
quate, the  wheel  will  not  work  to  the  highest  efficiency.  In  the 
days  of  geared  transmissions,  nothing  would  cause  gears — espe- 
cially those  running  at  high  speed — to  break  or  to  wear  out  faster 
than  a  weakness  developing  in  the  shaft  timbering.  The  author 
has  seen  high  speed  cut  gearing  stripped  of  its  teeth  by  poor 
timbering;  shafts  have  broken  and  hangers  have  been  torn  down 
and  belts  tangled  up  and  cut  to  pieces,  all  because  of  timbering 
too  weak  to  stand  the  strain  placed  upon  it. 

When  taking  charge  of  a  power  transmission — particularly  a 


382  MILLWRIGHTING 

water-power  mill,  the  millwright  will  do  well  to  go  over  the  shaft 
timbering  very  carefully,  and  calculate  the  strains  upon  such  mem- 
bers as  seem  doubtful  as  to  strength  appearance.  And  such  weak 
members  as  are  found  should  be  carefully  strengthened  until  they 
are  fit  to  stand  the  strain  without  undue  deflection. 

PENSTOCK  BUILDING. 

The  millwright  has  been  called  upon  at  one  time  or  another 
to  construct  penstocks  of  all  sorts  of  material,  wood,  steel,  brick 
and  concrete  being  among  the  materials  which  must  be  used.  In 
all  cases  it  is  necessary  to  use  the  kind  of  material  which  can  be 
obtained  the  most  readily,  and  at  the  same  time  not  prove  too 
costly  to  work  and  which  will  not  decay  too  quickly. 

Penstocks  have  been  built  of  wood  for  many  years,  but  at 
the  present  time,  unless  located  in  a  remote  district  where  timber 
is  abundant,  steel  should  be  used  for  penstock  construction.  Con- 
crete may  be  used  for  penstock  construction,  but  it  is  not  to  be 
advised  unless  it  be  in  sections  which  are  to  be  deeply  buried  in  the 
earth.  For  penstocks  above  ground,  the  author  does  not  advocate 
the  use  of  concrete  for  the  reason  that  a  penstock  is  always  under 
tensile  strain,  and  it  is  not  good  engineering  to  subject  concrete 
members  to  strain  of  that  character.  This  being  the  case,  it  will 
be  necessary  to  put  steel  enough  in  the  concrete  construction  to 
safely  carry  all  the  tensile  strain. 

Not  only  must  steel  enough  be  put  in  to  carry  the  strain  of  the 
water  due  to  its  weight  and  static  pressure,  but  there  must  be 
enough  strength  to  withstand  any  "water-ram"  action  due  to  the 
sudden  closing  or  partial  closing  of  the  water-wheel  gates.  There 
also  must  be  strength  to  withstand  the  possible  settling  of  a  por- 
tion of  the  penstock  and  the  consequent  poor  distribution  of 
weights. 

All  these  things  being  considered,  it  is  evident  that  there  must 
be  steel  enough  put  in  the  penstock  to  carry  all  the  strains  to 
which  it  may  be  subjected,  including  those  of  external  shocks. 
As  this  is  exactly  what  the  steel  plate  penstock  has  to  do,  which 
contains  only  steel  enough  to  safely  do  that  work,  it  would  not 
be  profitable,  in  ordinary  cases,  to  put  in  as  much  steel  as  would 
make  a  plate  penstock,  and  then  daub  on  an  equal  additional  cost 
for  cement! 


WATER-WHEEL  SETTING  383 

SPILLWAYS  AND  WASTE  WATERWAYS. 

The  millwright  is  frequently  called  upon  to  construct  ways 
by  which  water  may  find  its  way  to  the  main  channel  when  the 
river  is  high  and  overflows  its  banks  to  the  danger  of  dam  or 
abutments.  In  cases  of  this  kind  it  is  necessary  to  build  some  kind 
of  a  floor  which  the  water  cannot  wash  out,  no  matter  how  high 
its  level  may  raise. 

One  of  the  best,  if  not  the  best,  method  of  constructing  a  water 
passage  of  this  kind  is  to  provide  as  smooth  a  foundation  as  pos- 
sible, leveling  off  the  ground  as  necessary  and  placing  a  founda- 
tion such  as  can  be  best  made  with  the  material  at  hand.  If  rock 
is  plentiful,  put  in  a  rip-rap  of  the  largest  stones  available,  fill  the 
irregularities  with  smaller  stones  and  spread  on  a  thin  layer  of 
concrete — not  more  than  a  couple  of  inches  will  be  necessary. 
Next,  cover  the  concrete  with  wirecloth  of  a  size  and  mesh  in  pro- 
portion to  the  load  to  be  carried. 

If  the  location  is  such  that  never  more  than  a  foot  of  water 
will  run  over  the  spillway,  then  calculate  the  strength  of  wire-cloth 
necessary  to  sustain  that  amount  of  water  over  areas  as  large  as 
apt  to  be  undermined  in  case  of  trouble  of  that  kind.  The  spill- 
way is  to  be  treated  the  same  as  a  floor  or  a  roof.  If  there  is  a 
possibility  or  a  probability  that  it  may  be  undermined  and  hang 
suspended  on  boulders,  ledges  or  timbers  six  feet  apart  in  either 
direction,  then  calculate  the  amount  of  steel  necessary  in  wire- 
cloth  to  sustain  the  weight  of  the  probable  depth  of  water  on  the 
spillway. 

The  steel  section  having  been  determined  as  above — and 
exactly  as  for  any  other  reinforced  concrete  surface — spread  the 
wire-cloth,  then  cover  it  with  a  layer  of  concrete,  two  to  six  inches 
in  thickness,  according  to  the  amount  of  water  to  be  handled.  A 
spillway  constructed  in  this  manner  is  very  elastic.  In  case  it  be 
undermined,  it  will  hang  together  within  limits  of  the  steel 
strength  and  still  carry  away  the  water,  even  though  it  be  heaved 
about  in  places  and  sagged  into  all  sorts  of  curves. 

During  construction  work,  temporary  spillways  are  easily  made 
by  simply  spreading  light  wire-cloth  along  the  path  of  the  pro- 
posed water  course,  the  cloth  being  laid  upon  sticks,  strips  of 
board,  small  poles  or  any  material  which  will  serve  to  keep  the 
wire  netting  an  inch  or  so  away  from  the  ground.  Then  spread 


384  MILLWRIGHTING 

a  couple  of  inches  of  concrete  on  the  netting,  and  a  waterway  will 
be  secured  which  will  stand  a  great  deal  of  hard  usage,  and  which 
will  be  almost  as  flexible,  comparatively  speaking  of  course,  as  a 
blanket. 

CANALS  AND  WHEEL  PITS. 

It  is  no  longer  necessary  for  the  millwright  to  dig  a  long  canal 
for  bringing  the  water  to  the  mill  site,  and  it  is  no  longer  necessary 
to  dig  a  pit  big  enough  to  put  the  mill  in.  As  stated  on  page  376 
the  wheel-pit  is  no  longer  necessary,  and  the  steel  penstock  tube 
is  usually  much  cheaper  than  the  flume.  The  canal  may  be  used 
for  long  distances,  but  it  is  sometimes  more  profitable  to  locate 
the  water  wheel  independently  of  the  mill  and  use  electric  trans- 
mission. 

Where  light  canals  are  to  be  placed  in  porous  soils,  the  wire 
netting  concrete  blanket  described  in  the  preceding  paragraph 
makes  a  first-class  lining  for  a  canal.  It  also  has  the  advantage  of 
being  proof  against  muskrats.  When  a  loam  embankment  has  to 
be  erected  to  serve  as  a  dam  for  retaining  water,  in  place  of  the 
puddled  clay  core  just  try  the  concrete  wire-cloth  blanket.  It  is 
wonderfully  strong  and  fully  as  cheap  as  the  puddled  clay  core 
and  it  may  be  made  continuous  by  simply  lapping  the  wire-cloth 
a  few  inches. 

FOUNDATIONS  IN  BOG  AND  QUICKSAND. 

When  a  foundation  has  to  be  secured  in  a  bog,  or  upon  a  bed 
of  quicksand,  in  addition  to  the  conventional  methods  of  depositing 
brush,  stone,  logs  or  bags  of  concrete,  or  of  dumping  in  a  hetero- 
geneous mass  of  concrete,  the  millwright  will  find  that  a  wire- 
cloth  blanket  makes  one  of  the  best  beginnings  for  a  foundation 
which  can  be  constructed.  It  is  far  ahead  of  brush,  hay  or  timbers 
for  building  a  foundation  upon  and  it  is  easily  constructed,  either 
above  or  below  water. 

DAMS  AND  APRONS. 

When  the  millwright  meets  with  the  problem  of  constructing 
dams  in  alluvial  streams,  the  great  question  is  to  prevent  the  water 
from  breaking  through  under  the  dam,  which  must  be  placed  upon 
timbers  imbedded  in  the  sand — mud-sills,  as  they  are  technically 


WATER-WHEEL  SETTING 


385 


termed.  If  possible,  the  owners  should  be  induced  to  put  in  con- 
crete construction  with  enough  reinforcement  to  withstand  the 
strain  of  any  freshet  that  may  ever  get  at  the  dam.  The  great 
danger  is,  as  stated,  the  undermining  of  the  structure,  and  this 
may  be  prevented  by  using  the  concrete  blanket  for  some  distance 
above  and  below  the  dam. 

The  dam  proper  may  be  constructed  of  any  available  material, 
the  blanket  being  used,  simply  for  the  purpose  of  guarding  against 
undermining  of  the  structure.  There  is,  however,  a  method  of 
utilizing  wire-cloth  for  the  entire  structure,  the  scheme  being 
diagramatically  shown  by  Fig.  141,  in  which  a  represents  a  wire- 
cloth  apron,  extended  as  far  down  stream  as  local  conditions  make 
necessary.  Both  ends  of  the  apron  are  imbedded  in  the  bottom  of 


FIG.    141.— WIRE-CLOTH    DAM    FOR    ALLUVIAL    STREAMS. 

the  river  as  deeply  as  it  is  possible  to  excavate.  Upon  apron  a 
is  placed  a  pile  of  dirt,  stones,  logs,  brush,  ashes,  and  any  other 
matter  which  can  be  obtained.  When  earth  rilling  is  used,  one 
part  of  cement  is  mixed  with  it  by  sifting  it  into  the  wheelbarrows 
during  the  filling  operation,  one  shovelful  of  cement  being  used  to 
99  parts  of  earth,  the  number  of  shovelfuls  to  a  barrow  being 
counted  a  few  times  and  the  necessary  amount  of  cement  thus 
determined.  The  cement  and  earth  is  put  in  place  dry.  It  is 
mixed  by  the  handling  during  its  placing,  but  it  is  not  wetted  at 
any  time.  That  is  left  to  the  river  and  to  natural  moisture. 

The  filling  is  tamped  as  firmly  as  possible  along  the  line  b, 
the  angle  of  which  must  not  exceed  the  angle  of  repose  of  the 
material  used,  which,  if  sand,  will  be  30  degrees,  while  if  of 
clayey  material,  it  may  approach  60  degrees.  After  the  layer  a  b 
has  been  put  in  place,  lay  down  another  wire-concrete  ''blanket," 


386  MILLWRIGHTING 

the  wire  being  simply  laid  down  upon  a  thin  coating  of  con- 
crete and  another  thin  coating  spread  over  the  wire-cloth  which  is 
strengthened  by  lapping  the  strips,  according  to  necessity.  The 
concrete  had  best  be  made  of  aggregate  not  over  %  inch  in  diame- 
ter in  order  that  the  blanket  may  be  kept  clown  to  about  2  inches 
in  thickness. 

Proceed  in  like  manner  to  place  filling  b  c,  ramming  and 
smoothing  as  before ;  then  lay  down  blanket  c,  and  so  continue 
until  the  required  hight  is  reached.  The  last  blanket  c  is  to  be 
extended  up  the  stream  as  far  as  necessary  to  prevent  the  water 
from  getting  under  the  dam.  In  some  cases  it  may  be  necessary 
to  extend  this  layer  100  feet  or  more  up  stream.  The  ends  of  the 
blankets  which  come  against  the  river-bed  are  extended  as  far 
into  the  earth  as  it  is  possible  to  excavate.  A  dam  built  in  this 
fashion  will  stand  a  great  deal  of  wear,  and  even  if  the  layer 
filling  should  wash  out  to  a  considerable  extent  little  damage 
will  result.  The  up-stream  end  of  each  blanket  may  be  extended 
as  far  as  thought  necessary  for  the  safety  of  the  structure. 

SETTING  HYDRAULIC  RAMS. 

Where  only  a  small  portion  of  the  available  water  is  required, 
an  hydraulic  ram  may  be  used  to  advantage.  It  is  possible  to 
force  water  200  feet  high  with  a  well-arranged  ram,  but  several 
conditions  must  be  filled  in  order  to  secure  such  service.  Water 
may  also  be  conveyed  3000  feet  with  a  ram,  but  the  quantity 
delivered  at  such  extreme  distances  must  necessarily  be  but  a 
very  small  proportion  of  the  amount  of  water  delivered  to  the  ram. 

In  tests,  the  highest  efficiency  obtained  from  a  ram  was  74.9 
per  cent.,  but  this  varies  according  to  the  ratio  of  lift  and  fall, 
being  greater  at  low  than  at  high  ratios.  Clark  gives  the  follow- 
ing percentages  of  efficiency  for  ratios  varying  from  4  to  26 :  ' 

Ratio  of  lift  to  fall 4     6     8  10  12  14  16  18  20  22  24  26 

Efficiency    per    cent 72  61  52  44  37  31  25  19  14     9     4     0 

Thus  with  10  feet  head  and  40  feet  lift,  the  ram  would  show 
an  efficiency  of  72  per  cent.  But  with  10  feet  head  and  260  feet 
lift,  the  ram  could  just  raise  water  to  that  hight,  but  it  would 
be  unable  to  deliver  any;  hence  its  work  at  that  ratio  would 
have  no  efficiency. 


WATER-WHEEL  SETTING  387 

In  setting  rams,  the  millwright  should  look  to  it  that  freezing 
is  prevented.  Frost  is  a  deadly  enemy  of  the  hydraulic  ram  and 
so  is  vegetable  matter.  A  very  small  twig  or  root,  caught  between 
clack  and  seat,  will  put  the  best  ram  out  of  business  instantly  and 
completely.  To  prevent  occurrences  of  this  kind,  the  intake  should 
be  most  carefully  guarded,  and  should  never  be  permitted  to 
take  water  from  the  surface  or  from  the  bottom.  The  intermit- 
tent flow  of  water  into  the  intake  pipes  makes  it  particularly 
liable  to  draw  in  foreign  matter  with  the  water  supply. 

The  intake  pipe  of  a  ram  should  be  protected  by  a  large 
screen  surface  completely  surrounding  the  intake  pipe  and  at  a 
distance  of  several  inches  at  least  from  the  intake  pipe  opening. 
With  the  pipe  thus  screened  and  the  screen  wholly  submerged, 
and  no  portion  of  the  screen  resting  on  the  bottom  or  sides  of  the 
supply  well  or  stream,  there  should  be  little  trouble  from  clogging 
of  the  valve.  The  screen,  however,  must  be  regularly  inspected 
and  cleaned.  Frogs  frequently  put  a  ram  out  of  business  if  the 
screen  permits  their  getting  into  the  drive  pipe. 

One  point  in  particular,  and  a  vital  one,  is  apt  to  be  over- 
looked by  the  millwright  who  must  set  up  a  ram.  In  every  case, 
the  volume  of  the  feed  or  drive  pipe  should  equal  the  volume  of 
the  air-chamber  on  the  ram.  A  good  deal  depends  upon  this 
point,  and  frequently  the  poor  working  of  a  ram  may  be  traced 
directly  to  an  inequality  of  volume  between  the  two. 

Thus,  when  a  long  drive  pipe  must  be  used,  it  should  be  made 
smaller  in  diameter  in  order  that  it  fits  the  air-cylinder.  Again, 
a  man  may  think  that  a  pipe  a  size  or  two  larger  than  called  for 
by  the  opening  in  the  ram  will  give  all  the  better  results  for  being 
large,  and  is  puzzled  to  ascertain  why  the  ram  works  so  poorly 
when  he  went  to  the  trouble  and  expense  of  putting  in  such  a 
nice  large  drive  pipe?  He  did  not  know  that  by  putting  in  the 
larger  drive  pipe  he  had  "over-cylindered  his  engine,"  but  such 
is  the  fact. 

WATER  SUPPLY  AND  PUMPING  FOR  STEAM  AND  FOR  FIRE. 

Unless  there  be  unusual  conditions,  the  elevated  tank  for 
water  supply  is  most  desirable  for  factories  where  there  is  no 
city  water  service  or  other  supply  to  be  had  under  pressure.  The 
problem  of  boiler  washing  and  filling  is  solved  by  the  use  of  the 


388  MILLWRIGHTING 

elevated  tank,  and  when  a  tank  is  erected,  put  in  as  large  a  one 
as  possible.  The  regular  standard  water  tank  contains  35,000 
gallons  and  it  costs  little  more  to  put  in  a  tank  of  this  size  than 
it  does  to  install  one  of  one-third  that  capacity. 

For  pumping  into  a  tank,  never  attempt  to  use  a  boiler  feed 
pump,  especially  a  steam  pump,  for  to  do  so  costs  too  much. 
Use  a  tank  pump,  ana  even  then  the  cost  is  a  great  deal  more 
than  it  would  be  were  a  power  pump  used,  as  discussed  on 
page  354  in  connection  with  boiler  feeding.  The  electrically 
driven  pump  is  very  desirable  for  pumping  water  to  tank,  and 
when  connected  for  outside  "emergency  current"  a  most  excel- 
lent arrangement  is  effected,  making  the  water  supply  independ- 
ent of  shut  downs  of  boiler  and  engine. 

FIRE  HYDRANTS  AND  HOSE. 

It  does  little  good  to  provide  fire  hydrants  unless  some  of  the 
mill  operatives  are  regularly  drilled  as  a  fire  company.  The 
millwright  who  is  requested  to  organize  and  maintain  a  fire 
department  which  will  be  of  any  practical  value  in  case  of  fire, 
must  drill  his  company  with  as  much  care  and  persistence  as  is 
practised  in  a  regular  fire  department. 

In  locating  hydrants  and  hose,  it  does  very  little  good  to  run 
a  stand  pipe  through  the  factory  floors,  attach  a  length  of  hose 
on  each  floor  at  every  stand  pipe  and  then — never  touch  the  hose 
again  until  fire  breaks  out.  Hose  thus  connected  and  left  for 
months  or  years  is  almost  sure  to  be  found  rotted  away  where 
leakage  from  the  valve  has  kept  the  fabric  wet  during  many  long 
weeks.  The  author  regards  factory  distributed  stand  pipes  and 
hose  as  almost  utterly  worthless  for  fire  protection.  In  fact,  it 
is  utterly  worthless  unless  some  man  has  made  it  his  business  to 
keep  everything  in  order  and  the  system  is  tested  at  least  weekly 
by  actual  use.  If  an  efficient  fire  hose  system  is  to  be  main- 
tained in  the  mill,  it  must  be  taken  care  of,  and  time  at  least  equal 
to  that  of  one  man  must  be  spent  in  care  of  the  system. 

Hydrants  located  inside  the  factory  buildings  are  hardly  worth 
putting  in.  Locate  the  hydrants  outside  of  the  buildings  and  give 
adequate  protection  from  frost.  Keep  the  hose  on  a  reel  or  in  a 
hose  wagon  and  train  a  hose  company  to  use  the  fire  material. 
Then,  and  only  in  that  manner,  will  there  be  any  protection  in 
the  outlay  of  several  thousand  dollars  for  pipe  and  hose. 


WATER-WHEEL  SETTING  389 

LOCATING  AND   PIPING   AUTOMATIC    SPRINKLERS. 

The  only  adequate  method  of  fire  protection  for  factory  build- 
ings is  a  well  arranged  system  of  automatic  sprinklers.  But 
sprinkler  systems,  as  well  as  stand  pipe  and  hose,  must  be  taken 
care  of  and  tested  frequently  and  periodically.  In  all  fire  fighting 
apparatus,  it  must  be  one  man's  business  to  take  care  of  the  out- 
fit and  he  must  know,  from  actual  tests  and  trials,  that  everything 
is  O.  K. 

There  are  two  systems  of  automatic  sprinkler  fire  protection, 
the  wet  and  the  dry  systems.  In  the  first  the  pipes  are  at  all  times 
kept  full  of  water  and  under  pressure,  the  water  being  at  each 
sprinkler  ready  for  instant  use.  In  the  other,  or  "dry"  system,  the 
pipes  are  under  air  pressure  all  the  time,  the  water  being  kept 
out  of  the  sprinkler  system  by  means  of  an  automatic  valve  which 
admits  water  whenever  the  air  pressure  in  the  system  is  lowered 
by  the  opening  of  one  or  more  of  the  sprinkler  heads. 

Both  systems  have  their  good  and  their  bad  points,  and  the 
millwright  must  understand  and  humor  each,  as  may  be  necessary 
by  the  system  in  use.  Seemingly,  the  wet  system  is  ideal  for  the 
water  is  there  ready  for  instant  use.  But  water  will  rust  iron, 
and  the  pipes  may  become  completely  closed  with  oxide  deposits, 
the  openings  into  sprinkler  heads  become  rusted  over  and  water 
fails  to  issue  when  a  head  acts  under  heat.  Again,  there  is  the 
unpleasant  and  ever-present  danger  from  leaks  in  the  pipes  com- 
prising the  system.  The  many  hundreds  of  feet  of  pipe  in  a  large 
system  are  each  and  all  prepared  at  an  instant's  time  to  deluge 
the  factory  with  water  should  a  belt  happen  to  fly  off  its  pulleys 
and  break  a  pipe  or  tear  off  a  sprinkler  head. 

Somebody  must  be  continually  going  over  the  system  and 
removing  and  cleaning  sprinkler  heads,  and  making  sure  that  the 
pipes  are  not  clogged  with  rust  or  sediment.  This  man  must 
be  all  the  time  looking  for  leaks,  and  blowing  out  the  main  pipes 
to  keep  them  clear  of  rust. 

When  the  dry  system  is  used,  the  same  man  has  his  work  cut 
out  for  him.  He  must  be  alive  all  the  time  to  see  that  leaks  do 
not  exist  in  the  sprinkler  pipes,  for  leakage  here  will  cause  the 
air-pressure  to  fall  and  then  down  comes  the  water.  Another 
thing  to  contend  with  in  the  dry  system  is  the  necessity  for  keep- 
ing the  pipes  so  alined  that  drainage  is  readily  effected  after  the 


390  MILLWRIGHTING 

water  has  been  turned  on,  either  accidentally  or  during  tests.  A 
little  water  left  in  a  pipe  will  rust  even  quicker  than  when  the 
pipe  is  full  of  water,  hence  the  millwright  has  plenty  to  do  in  keep- 
ing the  pipes  free  from  water  after  each  test. 

The  valve  used  upon  dry  systems  has  an  uncomfortable  habit 
of  frequently  acting  without  orders,  and  the  sprinkler  pipes  will 
be  found  full  of  water  without  any  excuse  for  that  condition, 
making  necessary  the  drainage  of  the  pipes  again  and  the  reset- 
ting of  the  valve. 

Yet,  with  all  their  faults,  these  two  systems  are  very  desirable, 
and  the  millwright  must  become  acquainted  with  the  requirements 
of  both  and  be  able  to  install  and  keep  in  order  the  one  he  finds 
the  best  adapted  to  the  case  in  hand.  The  sprinkler  system,  to  be 
of  the  highest  efficiency,  must  be  most  carefully  laid  out,  the  sizes 
of  the  several  pipes  must  be  acurately  calculated  to  handle  the 
exact  number  of  sprinkler  heads  dependent  upon  that  pipe.  The 
best  method  of  maintaining  pressure  must  be  found  and  adopted, 
and  then  the  millwright  may  be  sure  that  the  system  will  be  an 
efficient  one  as  long  as  it  is  properly  taken  care  of. 


INDEX 


PAGE 

Accelerated  test  for  cement 66 

Accurate  sighting  over  a  level 44 

Actual  and  nominal  pipe  diameters.  303 
Adjusting  and  mounting  cross-hairs      49 

engine  center  line 333 

engine  main  bearing 335 

sights  on  a  carpenter's  level 543 

A-frame  pier,  erecting  an 117 

Air  and  water  traps 316 

Albany  grease 296 

Alinement  of  engine  shaft,  checking  335 

Alinement  of  shafting,  final 230 

Alining  rod,  plain 234 

shafting  with  a  plumb-bob,  268,  269 

the  engine 331 

Alloys,  bearing,  making 280 

bearing  metal 279 

Alluvial  streams,  dam  for 385 

Anchor  bolts,  setting  with  the  transit .   325 

who  shall  furnish 330 

Angle,  right,  laying  off  with  a  radius 

board 52 

Appliances,  boiler  feeding 264 

Aprons  and  dams 384 

A-piers  for  long  shafts. 116,  117 

Arch,  the  back 349 

Ash  and  coal  handling 357 

Auger,  pod,  for  roll  boring 361 

Augers  and  bits 210 

Automatic  boiler  feed  ...    355 

lubrication 291 

sprinklers,  locating  and  piping .  .  389 

Babbitt-metal,  heating 285 

Babbitting,  preparing  a  bearing  for .  .  281 

scraping  and  lubricating 278 

Back  arch 349 

combustion  chamber 351 

Badly  arranged  pipe  connections ....  320 

Ball  and  roller-bearings 224 

Ball-bearing  screw-jack .  258 

Balloon  framing 96,  97 

Balls  in  bearings,  short  life  of 225 

Base  or  center  lines 15 

Batter-boards 31 

Batter-boards  and  stakes,  setting.  .  .  43 


PAGE 

Batter-boards,  erected  to  grade.    ...     33 
Batter-boards,  locating  and  erecting     32 

saw-cuts  in 34 

putting  up 35 

usual  appearance  of 32 

Batter-posts,  marking 40 

Beam,  calculating  a 172 

calculating  for  given  load 170 

Beams  and  girders 126 

Beams,  stress  in  steel 64 

strength  of 166 

Bearing  alloys,  making 280 

Bearing,  main  engine,  adjusting ....  335 

Bearing-metal  alloys 279 

Bearing  plates 177 

power  of  bolts  and  daps  on  side- 
wood  174,  175 

Bearing,  preparing  for  babbitting. .  .   281 

short  life  of  ball 225 

capillary-oiled 221 

drying  with  gasoline 282 

journal,  grease-cups  for 224 

journal,  liners  for 221 

journal,  setting  up 110 

journal,  side  scraper  for 290 

journal,  timber-crushing 178 

pin 227 

ring-oiling 221 

roller,  care  of 225,  226 

scraping 288 

six-ball,  designing 228 

soft  metal,  pouring 286 

solid,  pouring 288 

*hrust 225 

tools  for  scraping 289 

Bed,  fastening,  engine 334 

Belt  and  horse-power  diagram 240 

fastenings 249 

hooks,  Bristol 251,  252 

impregnated  stitched  cotton. .  .  .  246 

putting  on  the  engine 339 

testing  an  engine  governor 340 

Belting 237 

impregnated  stitched  cotton 199 

requirements  of  leather 245 

selecting 244 


391 


392 


INDEX 


PAGE 

Belt  joint,  weak „ 250 

Belt  or  gear  transmission 377 

Belt-power  diagram,  laying  out  a,  238,  240 

Belt  pull,  calculating  the 132 

on  shaft-supporting  piers.  .  133 

Belts  and  belting 237 

finding  length  of 241 

gandy,  data  required  for  select- 
ing   247 

parafin  filling  for 249 

Belt  shifter,  ordinary 272 

and  shifting 271 

distant  control 275 

rod  and  rope 274 

rope  controlled 275,  276 

Belts,  lacing 249 

putting  on  pulleys 255 

rope  hitch  for 256 

rubber,  selecting 246 

Belt  studs,  Blakes 252 

Belt-width  diagram 237 

Bending  moment 170 

Benzine,  specific  gravity  of 70 

Bin-supports,  shafting  on 115 

Bit,  expanding  a 374 

Bus  and  augers 210 

Bits  and  boring  368,  369 

for  repair  work 370 

repairing  worn  or  damaged  ....  374 

sharpening 375 

small 373 

Blake's  belt  studs 252 

Blocks,  iron  strapped,  strength  of  .  .  264 

pillow  vs.  drop  hangers 114 

table  of  working  strength  of .  .  .  264 

Blow-off  pipe,  boiler,  the 350 

Board,  radius 51 

for  laying  off  a  right  angle.  52 

principle  of  the 53 

squaring  a  line  with  the ...  52 

batter 31 

erected  to  grade 33 

locating  and  erecting 32 

putting  up 35 

usual  appearance  of 32 

Bog  and  quicksand,  foundations  in.  384 

Boiler  blow-off  pipe 350 

feed,  automatic 356 

pipe 350 

pumps,  high  duty 356 

feeding  appliances . . 354 

foundations,  excavating  for.  .  .  .  345 

grates  and  doors 353 

horizontal  setting 346 

setting,  horizontal,  side  elevation 

of 347 

steam 244 

stack  and  damper 353 

steam,  locating  a 344 


PAGE 

Boiler,  steam,  lugs  for  supporting  a,  348 
Bolt  arrangement,  defective  in  com- 
pression coupling 200 

failure  by  shearing 186 

Bolt-head,  shearing  strains  in  a ....    186 

Bolt-holes,  straight,  boring 208,  209 

Bolts,  anchor,  setting  with  the  tran- 
sit    325 

and  daps,  bearing  power  of,  174,  175 
and  links,  tightening  pulley ....   338 

pockets,  foundation 332 

and  rods  proportioning.  . .  .  118,  119 

effect  of  side-overload  on 176 

joint,  holding  power  of 181 

table    of    diameter,    pitch    and 

strength  of 185 

Boring  and  bits 368,  369 

bolt  holes  straight 208,  209 

long  holes 371 

rolls,  pod  auger  for 361 

rig  for 359 

straight  holes 361 

through  knots  and  spikes 372 

Boss,  the  " Holler" 259 

Boxing,  or  cutting  daps 110 

or  dapping  tool 112 

Brackets  and  wall  shaft  hangers 124 

wall,  erecting 128 

Breaking  strength  of  timber 171 

Brick  laying 82 

Brickwork,  boiler,  starting 345 

Bridge-trees,  steel 9 

Brimstone,  setting  machines  writh . . .  268 

Bristol  belt  hooks 251,  252 

Broken  stone  and  sand  for  concrete      71 

Builder's  level  and  foundations 24 

laying  out  foundations  with 

"the 14 

laying  out 13 

Burning  of  lime 81 

Buyers  list,  machinery 202 

Cable  and  wire,  method  of  hoisting 

261,  263 

Cable-hoist  and  lever  lift 266 

Cable,  iron  and  steel,  table  of ......   262 

wire,  strength  of 262 

Calculating  a  beam 172 

for  given  work  or  load,  170,  171 
a  reinforced  concrete  footing.  .  .  86 
machinery  pier  of  reinforced 

concrete 86 

a  pier  footing  by  algebra 89 

steel  reinforcing 138 

strength  of  rafters 142 

the  belt  pull 132 

weight  necessary  in  a  pier 135 

pipe,  off-hand 303 

pipe,  rule  of  thumb 302 


INDEX 


393 


PAGE 

Callipers,  double 214 

Canals  and  wheel  pits 384 

Capillary  oiled  bearings 221 

Care  of  roller  bearings 225,  226 

Carpenter's  level,  adjusting  sights  on     45 
arranged      with      telescope 

sights  and  cross-hairs ...     47 
foundations  placed  with ...     38 

sighting  over  the 41 

using  with  a  plane-table ...     42 
Carrying  power  of  different  soils.  .  .     57 

Cast  washers,  table  of 184 

Causes  of  error  in  leveling 37 

Cement,  accelerated  test  for 66 

and  aggregates,  testing 64 

test  for  consistency  of  volume. .     65 

mortar,  lime  in 79 

pat  for  constancy  of  volume  test    66 
proportion  of,  for  concrete  ....      71 

setting  machines  with 268 

specific  gravity  and  time  of 

setting 68 

tensile  tests  of 67 

testing  fineness  of 65 

testing-screens  or  sieves 69 

testing  specific  gravity  of 69 

Center  line  of  engine,  adjusting  the.   333 

or  base  lines 15 

Centering  head  end  of  cylinder 332 

line  in  gland 333 

Chain  hoists,  differential  using 260 

or  ring  lubrication 291 

Chalk  lines,  locating  and  fastening  .     34 

Chamber,  back  combustion 361 

Channels,  forming  oil 284 

Chart,  length  of  belt,  laying  out  a,  242,  243 

Check  and  stop  valves 353 

Checking  alinement  of  engine  shaft..  335 

Circulating  oil  system •  .  .   292 

Clamp,  yoke 127 

Clay  or  putty  dams 284 

Cleaning  door  and  back  combustion 

chamber , 351 

Clearance,  equalizing  the 336 

Clockwise  and  counter-clockwise.  .  .    148 

Coal  and  ash  handling 357 

Coefficient  of  expansion  of  concrete.     63 

of  iron 320 

Coefficients  of  elasticity  for  shear ....   191 

Cold  and  hot  glue 367 

Cold  test  for  oils 298 

Collars,  safety  set 229 

Compass-gun,  level  sights 44 

Combustion  chamber,  back 351 

Component  and  resultant  forces 146 

Composition  roofs 155,  156 

Compression  coupling,  defective  bolt 

arrangement  in 200 

Compression  coupling 199,  200 


PAGE 

Compression,  strength 172 

Concrete,  coefficient  of 63 

construction 62,  83 

construction,  Ransome  system  of    87 

curve,  laying  out  a 75 

curves  for  proportioning 74,  75 

drilling  holes  in 129 

foundations,  shape  of 58 

proportioning  rock  and  sand  for .     71 
sand,  gravel  or  stone  for  ....      73 
proportions  of  cement  and  water 

for 71 

reinforced 63,  85 

reinforced,  economy  of  material 

by  using 137 

sand  and  broken  stone  for 71 

sand  quality  determination  for . .     77 
scientific  method  of  proportion- 
ing      74 

station  stones 25 

tests  of 63 

use  well-screened  rock  and  sand 

for 71 

with  fine  stone  or  gravel 79 

wood  floors 123 

hanging  shafting  to 123 

Connections,  making  up  flange 319 

badly  arranged  pipe 320 

Constancy  of  volume  test,  for  cement    65 

Constructing  a  stress  diagram 152 

a  templet 326 

Construction,  concrete 62,  83 

masonry 82 

Construction  of  flumes 376 

Copper  and  tin  roofs 158 

Copper  roofing 160 

Cotton  belt,  impregnated,  stitched . .  .   246 
Cotton  belting,  impregnated,  stitched  199 

Coupling,  compression 199 

flange,  improved  Hendershot. .  .  201 

flange  or  plate 200 

Covering  mandrels  with  paper 282 

Creep  of  belts 253,  254 

Cross    for    centering    head    end    of 

cylinder 332 

Cross-hair  instrument,  leveling  foun- 
dations with  a 29 

Cross-hairs,  adjusting  and  mounting .     49 
with    telescope    on    carpenter's 

level 47 

Cross-lines,  laying  down 22 

Crushing  strength  and  compression . .    173 

Curvature  of  the  earth 35 

Cutting  daps  or  boxing  timber 110 

gaskets  and  packing 323 

pillow  blocks 206 

pipe 310 

"Cutting"  of  valves  and  fittings 315 

Cut  washers,  table  of 182 


394 


INDEX 


PAGE 

Cylinder,  centering  head  end  of 332 

lubricator  for 341 

Damaged  bits,  repairing 374 

Damper  and  stack,  boiler 353 

Dams  and  aprons •  384 

clay  or  putty 284 

wire-cloth  for  alluvia-1  streams . . .  385 

Dap,  mortise  and  tenon 9 

Dapping,  or  boxing  tool 112 

Daps,  cutting 110 

bearing  power  of 174,  175 

Dead-ends  and  drips 317 

Deck  flume  framing 376 

Defective    bolt    arrangement    in    a 

compression  coupling 200 

Defective  pipe  and  fittings 313 

Designing  a  six-ball  bearing.  .  .  228 
Diameters  of  pipes,  actual  and  nom- 
inal   303 

triangle  of 302 

Differential  chain  hoists 260 

Dimensions  on  shaft  drawings 195 

Distant  control  belt  shifters 275 

Distance,  focal,  of  lenses 47 

Doors  and  grates,  boiler 353 

cleaning 351 

Double  calipers 214 

sighting  over  pulleys 231,  232 

Draft-tube  and  penstock  wheel  setting  378 

Draining  pipe  system 314 

Draw-bores,  marking 106 

Drawings,  shaft 193 

dimensioning  of 195 

Drilling  holes  in  concrete 129 

Drip  pipes 342 

Drips  and  dead-ends 317 

Drop  hangers  vs.  pillow  blocks.  ...  114 

Drying  bearings  with  gasoline 282 

Duck,     pick,     weave,     stretch    and 

weight  of 247,  248 

Earth,  curvature  of  the 35 

Efficiency  of  hydraulic  rams 386 

Elasticity,  coefficients  of,  table 191 

Elastic  limit  of  soft  steel 164 

End  motion  to  shaft 230 

scraper  for  fast  work 290 

Enlarging  bored  holes 371 

Engine,  alining  the 331 

bed,  fastening  the 334 

belt,  putting  on  the „  339 

center  line,  adjusting 333 

governor  belt 339 

'    testing 340 

main  bearing,  adjusting  the. .  .  .  335 

pulley,  putting  on  the 337 

erecting  steam 324 

running  over  or  under 340 


PAGE 

Engine,  green  foundations,  placing  .  329 

shaft,  checking  alinement  of .  .  .  .  335 

Equalizing  the  clearance 336 

Erecting  a-frame  pier 117 

building  and  machinery  founda-  ' 

tions 56 

batter  boards 32 

steam  engines 324 

wall  brackets 128 

Erection  of  buildings 82 

Error  in  leveling,  causes  of 37 

Examination  of  work 331 

Excavating  for  boiler  foundations  . .  345 

Exhaust  and  drip  pipes,  and  heater.  342 

Expanding  a  bit 374 

Expansion  of  concrete,  coefficient  of     63 

of  iron,  coefficient  of 320 

of  steam  pipes 320 

Extreme  fiber  stress 169 

Face  corner,  working  from 108 

Factor  of  safety 164 

Factories,  laying  out  of 11 

Factory  location 11 

Fastening  chalk  lines 34 

engine  bed  in  position 334 

I-beams,  method  of 125 

Fastenings,  belt 249 

Feed,  automatic  boiler 356 

pipes,  boiler 350 

pump,  connecting  the 355 

pumps,  high  duty  boiler 356 

Fiber  stress,  extreme 169 

Filters  and  pumps,  oil 293 

Fineness  of-  cement,  testing 65 

Finishing  wooden  rolls. 363 

Fire-brick  furnace  lining 347 

Fire  hydrants  and  hose 388 

Fitting  a  machine  to  its  foundation.  267 

and  selection  of  pipes .  304 

keys  into  pulleys.  ............  214 

standard  pipe 305 

defective 313 

steam  and  water  pipes 299 

up  a  shaft 192 

Flange  connections,  making  up 319 

coupling,  improved  Hendershot.  201 

or  plate  coupling 200 

Flat  roofs 155 

Flooring  and  floors 121 

laying,  tongued  and  grooved  . .  .  123 

laying,  "1  and  2" 121,  122 

laying,  slow-burning 121 

Floors  on  concrete,  wood 123 

Flume  construction 376 

deck  framing 376 

Focal  distance  of  lenses 47 

Focussing  a  telescope 49 

Finding  obscure  leaks  in  pipes 313 


INDEX 


395 


PAGE 

Footing  problem,  solving  by  algebra    89 

calculating  a  reinforced 86 

Footings,  rule  for  pier 87 

Forces,  component  and  resultant .  .  .  146 

graphic  representation  of 147 

parallelogram  of 146,  148 

studying 146 

Form,  cheaply  constructed 61 

costly  and  troublesome 59 

Forming  oil-channels 284 

Forms,  making  and  placing 83 

placing  and  removing 64 

strength  of  wooden 84 

Foundation,  boiler,  excavating  for.  .  345 

bolts  and  pockets 332 

drawings,  wasteful 56 

fitting  a  machine  upon 267 

level,  determination  of 26 

Foundations  and  the  builder's  level .  24 

and  the  carpenter's  level 38 

concrete,  shape  of 58 

costly  taper-side 58 

erecting   for  buildings  and  ma- 
chinery  ,  56 

green,  placing  engines  upon  . .  .  329 

in  bog  and  quicksand 384 

leveling  with  a  cross-hair  instru- 
ment    29 

laying   out    with    the    builder's 

level 14 

laying  out  with  transit 14 

method  of  laying  out 13 

placing  machines  upon 285 

suspended 325 

to  absorb  vibrations 324 

Frame  structures 93 

Framing  a  decked  flume 376 

for  wheel  shafts 381 

laying  out 103 

on  the  job  and  at  the  mill 101 

timber  and  steel 9 

Fundamental   dimensions   on    shaft 

drawing 195 

Furnace  lining,  brick 347 

Gage  for  laying  out  framing 104 

Gandy  belts,  data  required  for  select- 
ing   247 

paraffin  filling  for 249 

Gaskets,  cutting 323 

Gasoline,  drying  bearings  with 282 

Gear  or  belt  transmission 377 

Gland,  centering  line  in 333 

Glue,  hot  and  cold 367 

using  and  preparing 367 

Graphical  truss  analysis,  notation  for  150 
Governor  belt,  testing  an  engine .  .  .   340 

Governors,  water  wheel 379 

Grade,  batter-boards  erected  to ....     33 


PACK 

Grading,  sand  and  gravel 73 

Graphic  representation  of  forces 141 

Grates  and  doors,  boiler 353 

Gravel  and  sand,  grading 73 

roofs,  laying  of 156 

Grease,    Albany 296 

Grease,  and  oil-cups,  spring-cover.  .  222 
Grease-cups  for  journal  bearings  . . .  224 

spring  cover 222 

Grease  lubrication 295 

Green  foundations,  placing  engines 

upon 329 

Gudgeons,  inserting  roll 362 

Hand  boring,  straight,  method  of  .  .  362 

Handling  ashes  and  coal 356,  357 

Hangers,  drop,  vs.  pillow  blocks.  .  .    114 

wall,  shaft,  and  brackets 124 

Hanging  shafting  to  concrete  work  .  123 
to  old   reinforced   concrete 

125,  126 

Harness-work,  steel 9 

Head  end  of  cylinder,  centering ....  332 

Heater,  engine 342 

Heating  babbit  metal 285 

Hendershot  improved  flange  coupling  201 

High  duty  boiler  feed  pumps 356 

Hitch,  rope  for  belts 256 

Hoisting  machinery,  caution  when 

using 261 

with    wire    cable    and    snatch- 
block 261,  263 

Hoists,  using  differential  chain 260 

Holding  power  of  joint-bolts 181 

Holding  power  of  set-screws  and  keys  217 

Holes,  boring,  long 

properly  proportioned  in  a  belt 

joint 250 

reaming  and  enlarging 371 

straight,  boring 361 

straight  boring  for  bolts .  .  .  208,  209 

"Holler-Boss"  the 259 

Home-made  leveling  telescope 46 

leveling-rod  or  staff 27 

testing  sieves 69 

Hooks,  Bristol  belt 251,  252 

Horizontal  bolier  setting  a 346 

Horse-power,  of  belts.  . 189 

diagram  of  belts .   240 

Hose  and  hydrants,  fire 388 

Howe  truss,  evolution  of  the 154 

Hydrants  and  hose,  fire 388 

Hydrated  lime  and  lime  mortar.  ...     80 

Hydrating  or  slaking  lime 80 

Hydraulic  rams,  efficiency  of 386 

setting 386 

Idle  fold  of  belt,  pull  on 134 


396 


INDEX 


PAGE 
Impregnated  stitched  cotton  belting 

199,  246 
Improved  flange  coupling,  the  Hen- 

dershot 201 

Inertia,  moment  of 168 

Injector  and  feed  pump,  connecting 

the 355 

Inserting  roll-gudgeons 362 

Inspection  during  erection 91 

Inspecting  for  graft 92 

Iron  and  steel  wire  cable,  table  of  .  262 
Iron,  coefficient  of  expansion  of.  ...  320 
Iron-strapped  blocks,  strength  of .  .  .  264 
Ironwork,  strength  of 185 


Jacking  up  machinery,  caution  in . 

Jack-screw,  ball-bearing 

substitute  for 

Jackson  steel  wire  belt  lacing 

Jacks,  whisky,  operation  of 

Joint-bolts,  holding  power  of 

Joints  of  truss,  stress  at 

Journal  bearings,  grease-cups  for . . 

liners  for 

setting  up 

side  scraper  for 

timber  crushing 


.  258 
.  258 
.  130 
.  253 
.  257 
.  181 
.  144 
.  224 
.  221 
.  220 
.  290 
.  178 


Kerosene,  specific  gravity  of 70 

Keying,  the  Woodruff  system  of. ...  218 

Keys,  fitting  into  pulleys 214 

holding  power  of 217 

shipping  in  pulleys 203 

Keyways  and  straight  shafting 218 

Knots     and     spikes,     boring     holes 

through 372 

Lacing  belts 249 

Lagging    pulleys    to    increase    their 

diameter 363 

Lag  patterns,  making  and  laying  out 

363,  364 

Lag-screws,  rolled-thread 118,  119 

Lake  Erie  sand 72 

Leaks  in  pipes,  finding 313 

Leaky  tin  roofs,  repairing  of 160 

Leather  belting,  requirements  of .  .  .    245 

Length-of-belt  chart 243 

laying  out  a 242 

Length  of  belts,  finding  the 241 

Lenses,  focal  distance  of 47 

mounting  in  a  tube 48 

Leveling  and  alining  rods,  plain 234 

a  line  of  stakes 39 

causes  of  error  in 37 

for  a  shaft 205 

foundations    with    a    cross-hair 

instrument 29 

long  and  short  lines 53,  54 


PAGE 
Leveling-rod  or  staff,  home-made ...     27 

plumbing  the 31 

reading  the 30,  31,  35 

use  of  a .     28 

Leveling  shafting,  rods  for 234 

telescope,  home-made 46 

with  a  transit 26 

Level  arranged  with  "gun-compass" 

sights 45 

carpenters,   arranged   with  tele- 
scope sights  and  cross-hairs.       47 
placing  foundations  with  the    38 

sighting  over  the 41 

using  with  a  plane  table ...     42 

sights,  "gun-compass" 44 

test,  final,  of  shafting 230 

the  builders 14,  24 

the  "Y"  or  "  wye"    13 

Levels,  long,  running 36 

foundation,  determination  of  ...     26 

Lever  and  cable-hoist  lift 266 

Lift  and  fall  in  hydraulic  ram  work . .    386 

Lift,  lever  and  cable-hoist 266 

Lighting,  saw-tooth 162 

Lights,  sky  and  monitors 161 

Lime  and  lime  mortar 79,  80 

Lime,  burning  of 81 

in  cement  mortar 79 

Line,  centering  in  gland 333 

squaring  a 50 

with  the  radius  board 52 

of  stakes,  leveling 39 

Lines,  base  or  center 15 

chalk,  locating  and  fastening. .  .     34 

leveling  long  and  short 53,  54 

secondary 15 

Liners  for  journal  bearings 221 

Lining,  furnace,  fire-brick    347 

out  for  a  shaft .   204 

up  pulleys 214 

journal  bearing,  peening 283 

Links  and  bolts,  tightening  pulley .  .  .   338 
Load-carrying    power     of    different 

soils 57 

Loads,  wind  and  snow 140 

Locating  and  erecting  batter-boards     32 

and  fastening  chalk  lines 34 

and  piping  automatic  sprinklers .  389 

the  steam  boiler 344 

Location  of  factory 11 

Long  and  short  lines,  leveling    .  .  .53,  54 

holes,  boring 371 

levels,  running 36 

rolls,  making 360 

Loop,  the  steam 319 

Lubricants  for  different  purposes . .  .   297 

Lubricating  bearings 278 

Lubrication,  automatic ............   291 

chain  or  ring .  , 291 


INDEX 


397 


PAGE 

Lubrication,  grease 295 

Lubricator,  cylinder 341 

Lugs  for  supporting  a  steam  boiler . . .   348 

Machine,  fitting  to  foundation 267 

for  testing  oil 294 

Machinery,  buyers'  list  of 202 

caution  in  jacking  up 258 

caution  when  hoisting 261 

foundations,  erecting 56 

receiving  at  the  mill 203 

supports  and  walls 114 

Machines,    lack    of    working    space 

around 12 

placing  upon  foundations 265 

setting  up 257 

Main  bearing  of  engine,  adjusting . .  335 

Mandrels,  covering  with  paper 282 

Manufacturing,  movement  of  mate- 
rial during 11 

Masonry  construction 82 

Materials,  strength  of 163 

transverse  strength  of 165 

Measurements,  shaft . . .  : 196 

Measuring  and  scaling  shafting  and 

drawings 196 

pipe  lines 309 

shafting 196 

the  forces  acting  at  a  point.  .  .  .  149 

Metal,  heating  babbitt 285 

Millwright  and  what  he  is 7 

qualifications  of  a 8 

vigilance  necessary  by  the 62 

Moduli  of  rupture 172 

Modulus,  section 169 

Monitors  and  sky  lights 161 

Mortise,  tenon  and  "dap" 9 

Mounting  and  adjusting  cross-hairs . .  49 

lenses  in  a  tube 48 

Nominal    and    actual    diameters   of- 

pipes 303 

Notation  for  graphical  truss  analysis .    150 

Offsets  for  solid  masonry  footings.  .  90 
Oil  and  paraffin  filling  for  Gandy 

belt 249 

Oil-cap  and  nipple  oilers 223 

Oil-channels,  forming 284 

Oil-cups,  spring  cover 222 

Oiled  bearings,  capillary .  221 

Oilers,  oil-cap  and  nipple 223 

Oil  filters  and  pumps 293 

Oils  and  oil  testing 293 

Oils,  cold  test  for 298 

Oil  system,  circulating .' .  292 

test,  glass 294 

testing 293 

machine . .                            .  294 


PACK 

Operating  a  plane-table 42 

Operation  of  whisky  jacks 257 

Ordinary  belt  shifter 272 

Ottawa,'  111.,  standard  sand 72 

Packing  and  regrinding  valves 321 

Packing,  cutting 323 

Paper,  covering  mandrels  with,  when 

babbitting 282 

Paraffin  filling  for  Gandy  belts 249 

Parallelogram  of  forces 146,  148 

Peening  soft  linings 283 

Pen  stock  and  draft-tube  wheel  setting  378 

Pen  stock  building 382 

Permanent  stations  or  targets ......     15 

targets 14 

Personal  examination  of  work  during 

erection 331 

Perspective  pipe  layout 308 

Pick,  weave,  stretch  and  weight  of 

duck 247,  248 

Pier,  a-frame,  erection  of 117 

calculating  weight  necessary  in  a   135 

footing,  calculating 89 

rule  for 87 

Piers,  shaft  supporting,  belt  pull  on .  .   133 

Pillow-block,  cutting  in  a 206 

vs.  drop  hangers 114 

Pin  bearings 227 

Pipe,  blow-off,  the  boiler 350 

calculations,  off-hand 303 

rule  of  thumb 302 

connections,  badly  arragned.  .  .   320 

to  safety  valve 352 

cutting  off . .' 310,  311 

defective 313 

expansion  of  strain 320 

fitting 299 

standard 305 

layout,  perspective 208 

lines,  measuring 309 

making  up  joints  in 322 

actual  and  nominal  diameters  of  303 

boiler  feed,  the 350 

finding  leaks  in 313 

selection  and  fitting 304 

Pipe  standards,  eastern  and  western  304 

system,  draining 314 

threading 311 

triangle  of  diameters 302 

tongs  and  their  use 315 

tools,  abuse  of 316 

Piping  and  locating  automatic  sprink- 
lers  389 

laying  out 307,  308 

Pits,  wheel  and  canals 384 

Plane  table  and  the  carpenter's  level 

using  a 42 

operating  the 42 


398 


INDEX 


PAGE 

Plane  table,  rudimentary 41 

Plan  for  setting  a  horizontal  boiler  346 
Plaster  method  of  machine  setting . .  267 

Plate  or  flange  coupling 200 

Plates,  bearing 177 

Plumb-bob,        alining        machinery 

with  268,  269 

Plumbing  the  leveling  rod 31 

Pockets,  foundation 332 

Pod  auger  for  roll  boring ......   361 

Points  or  stones,  station' 18 

Pole  and  tape-line,  use  of 50 

Pouring  soft  metal  bearings 286 

Pouring  thin  solid  boxes  or  bearings  288 

Power  of  shafting 188 

Pratt  truss,  evolution  of  the 155 

Preparing  and  using  glue 367 

bearing  for  babbitting 281 

Pressure,  wind,  adjustment  of  strains 

of 145 

Proportioning  bolts  and  rods ....  118,  119 
cement,  sand  and  stone  or  gravel 

for  concrete 73 

concrete,  curves  for 74,     75 

scientific  method  of .......     74 

rock  and  sand  for  concrete.  ...     71 

Proportions  of  sand  and  cement  for 

various  sizes  of  stone 78 

Pull  of  a  belt,  calculating  the 132 

on  working  and  on  idle  folds  of 

a  belt 134 

Pulley,    belt    and    horse-power   dia- 

'  gram 240 

bolts  and  links,  tightening 338 

putting  on  engine 337 

lining  up 214 

putting  in  place   without   hoist- 
ing tackle 213 

wood,  building  in  flange 300 

Pulleys,  double  sighting  over.  .  .231,  232 

fitting  keys  into 214 

lagging 363 

putting  belts  on 255 

putting  in  place 212 

shipping  keys  in 203 

Pump,  boiler  feed 355 

Pumping  water  for  fire  and  for  steam  387 

Pumps  and  fitting  for  oil 293 

high  duty  boiler  feed 356 

steam 357 

Putty  or  clay  dams , , 284 

Qualifications  of  a  millwright 8 

Quicksand  and  bog,  foundations  in.  384 

Radius  board 51 

for  laying  off  a  right  angle  52 

principle  of  the 53 

squaring  a  line  with  the .  .  52 


Rafters,  calculating  strength  of .... 
Rams,  hydraulic,  efficiency  of  .... 
ratio  of  lift  and  fall  in .  . 


PACK 
.  142 
.  386 
.  386 
.  386 
.  88 
87 
28 
,  35 
371 
203 
153 


setting 

Ransome  bars,  table  of 

system  of  concrete  construction 

Reading  a  Vernier 

the  leveling-rod 30,  31 

Reaming  and  enlarging  holes 

Receiving  machinery  at  the  mill 

Record  of  strain 

Recrystallization     and     "Burning" 

lime 81 

R  egrinding  and  packing  valves 321 

Reinforced  concrete 63,  85 

economy  of  material    by    using  137 

Reinforcing  steel 138 

Removing  forms 64 

Repair  work,  bits  for 370 

Repairing  damaged  or  worn  bits.  .  .   374 

leaky  tin  roofs 160 

Representation  of  forces,  graphic . .  .    147 
Requirements  of  leather  belting.  .  .  .   245 

Resistance  to  shearing 183 

Resultant  and  component  forces ....   146 

Rifle  telescope 50 

Rig  for  boring  rolls 359 

Right  angle,  laying  off  with  a  radius 

board  . . ". 52 

Ring  lubrication 291 

split  for  roll-end 363 

Rings,  thrust 225 

Rocking  horse   substitute   for  jack- 
screw  130 

Rod  and  rope  belt  shifters .   274 

Rod,  leveling,  use  of  a 28 

for  leveling  shafting 234 

making  long 360 

plain,  for  leveling  and  alining .  .  .   234 

proportioning 118,  1 19 

station 20 

station,  long  and  short 22 

Roll  boring,  pod  auger  for 361 

Rolled-thread  lag-screws 120 

Roll-end    split  ring  for 363 

Roll-gudgeons,  inserting 362 

Roller  bearings 224 

care  of 225,  226 

Rollers  and  skids 257,  259 

Rolls,  finishing  wooden 363 

turning  without  a  lathe 360 

wooden 358 

Roof  covering,  weight  of 141 

composition 155,  156 

copper  and  tin ............  158,  160 

flat 155 

laying  tar  and  gravel 156 

slate 160 

tin,  repairing  leaky 160 


INDEX 


399 


PAGE 

Roof,  wind  and  snow  loads  on 140 

timbering  and  trusses 140 

trusses 141,  143 

Rope  and  rod  belt  shifters 274 

Rope-hitch  for  belts 256 

Rubber  belts,  selecting 246 

Rudimentary  plane  table 41 

Running  engines  over  or  under.  .  .  .  340 

long  levels 36 

levels  with  the  straight-edge  and 

carpenter's  level 38 

Safety,  factor  of 164 

valve  and  steam  pipe  connections  352 

set  collars 229 

Sand  and  broken  stone  forconcrete .  .  71 

and  cement  testing  sceens 69 

and  gravel,  grading 73 

lake  Erie 72 

quality  determination 77 

standard 72 

Saw-cuts  in  batter-boards 34 

Saw-mill  arrangement 12 

Saw-tooth  lighting 162 

Scale-making  and  reading,  vernier  28 

Scaling  and  measuring  shafting.  .  .  .  196 
Scientific    method    of    proportioning 

concrete 74 

Scraper,  end,  for  fast  work 290 

side,  for  bearings 290 

Scraping  bearings 278,  288 

tools  for 289 

Screens  for  testing  cement 69 

or  sieves,  sizes  and  numbers.  .  .  76 

Screws,  set,  holding  power  of 217 

lag;    rolled-thread 118,  119 

set 216 

Secondary  lines 15 

Secc  nd-hand  transit,  cost  of 13 

Section  modulus 169 

Set-screws 216 

and  keys,  holding  power  of . .  .  .  217 

Setting  anchor  bolts  with  the  transit . .  325 

batter-boards  and  stakes 43 

for  steam  boiler 244 

hydraulic  rams 386 

machines,  plaster  method  of .  .  .  267 
machines  with  cement,   plaster 

and  brimstone 268 

machines 257 

water  wheels 376 

wheels  with  penstock  and  draft- 
tube 376 

Shaft  drawings 193 

Shafting,  alining  with  a  plumb-bob 

268,  269 

erector's  list  of 197 

final  alinement  of 230 

final  transit  test  of 233 


PAGE 

Shafting,  hanging  to  concrete  work.    123 
hanging   to   old   concrete   work 

125,  126 

horse-power  of 188 

hung  to  balloon  frame 98,  99 

laying  out 188 

measuring  and  scaling 196 

on  bin-supports 115 

rods  for  leveling 234 

straight  and  key  ways 218 

walls  for  supporting 116 

Shaft,  fitting  up  a 192 

hangers  for  wall  and  brackets..  124 

laying  out  a 194 

leveling  for  a 205 

lining  out  for  a 204 

measurments 196 

straightening  a 219 

straightening,  theory  of 220 

supporting  piers 131,  132 

belt  pull  on 133 

torsion  in  a 189 

Shafts,  a-pier  for.  .  .  .  •. 116,  117 

framing  for  water  wheel 381 

stiffness  of 191 

testing  without  the  transit 335 

torsional  stress  in 190 

twisting  moment  of 190 

Sharpening  bits 373 

Shear,  coefficients  of  elasticity  for  . .   191 

Shearing,  bolt  failure  by 186 

resistance  to 183 

strains  in  a  bolt  head 188 

strength  of  timber 179,  180 

Shifter,  ordinary 272 

Shifters,  belt,  rod  and  rope 274 

Shifter,  rope  controlled 275,  278 

Shifting  belts 271 

Shipping  keys  in  pulleys 203 

Shop  work 358 

Short  and  long  lines,  leveling 53,  54 

station  rods 22 

Side  elevation    of    horizontal    boiler 

setting «. 347 

scraper  for  journal  bearings  . .  .  290 

Sieves  for  testing  cement 69 

or  screens,  sizes  and  numbers . .     76 

Sighting  accurately  over  a  level.  ...     44 

and  spotting  timber  out  of  wind  110 

double,  over  pulleys 231,  232 

over  the  carpenter's  level 41 

strips  arranged  on  level 44 

Sights,  adjusting  on  a  carpenter's 

level 45 

telescope  on  a  carpenter's  level     47 

Simple  roof  truss 142,  143 

Six-ball  bearing,  designing  a 228 

Six,  eight  and  ten  method  of  squaring 

aline . ...     51 


400 


INDEX 


PAGE 

Sizing  timber 95 

Skids  and  rollers — the  whisky  jack.  257 

using 259 

Sky-lights  and  monitors , 161 

Slaking  or  hydrating  lime 80 

Slate  roofing 100 

Slow-burning  flooring,  laying.  .....    121 

mill  construction    99,  100 

Stress  in  steel  beams 64 

Small  bits 372 

Snatch-block  and  wire  cable  hoist .  .   236 

Snow  and  wind  loads 140 

stress  at  joints  of  truss 1 44 

Soft  linings,  peening 

metal  bearings,  pouring 286 

steel,  elastic  limit  of 164 

Soils,  load  carrying  power  of  different     57 
Solid  boxes,  pouring .  . 
Solving  the  footing  problem  by  alge- 
bra      89 

Some  old-time  framing 94 

shop  work . . .  . 358 

Specific    gravity  and  time  of  setting 

of  cement 68 

of  cement,  testing 69 

of  kerosene  or  benzine 70 

Spectacle  pipe  telescope 49 

Spikes,  boring  holes  through 372 

Spillways  and  waste  waterways 383 

Split-ring  for  roll-end 363 

Spotting  and  sighting  timber  out  of 

wind 110 

timber 11.0 

Spring-cover  grease  and  oil-cups  . . .  222 
Springing  two-inch  planks  into  place  122 
Sprinklers,  automatic,  locating  and 

piping 389 

"Squaring"      line 50 

Squaring  a  line,  the  six,  eight  and  ten 

method  of 51 

with  the  radius  board  ....     52 

around  a  timber 108,  109 

the  engine  shaft 334 

station  rod 22 

Stack  and  damper,  boiler 353 

Station  points  or  stones. 18 

rod 20 

squaring  a 22 

use  of 21 

rods,  long  and  short 22 

rod  method,  advantages  of.  ...      23 
Stations   and   sub-stations,   arrange- 
ment of 19 

or  targets,  permanent 15 

Station  stones 14 

concrete 25 

cost  of 25 

Stakes  and  batter-boards,  setting.  .  .     43 
leveling  a  line  of 39 


PAGE 

Standard  pipe  fitting 305 

sand , 72 

valves 305 

Standards,  pipe,  eastern  and  western  304 

Starting  the  boiler  brickwork 345 

Steam  and  water  pipe  fitting 299 

boiler,  locating  a 344 

lugs  for  supporting  a 348 

setting 344 

engines,  erecting 324 

loop,  the 318,  319 

pipe  connections  to  safety  valve     352 

expansion  of 320 

line,  laying  out 299 

traps .357 

Steel  and  timber  framing ,  .       9 

beams,  stress  in 64 

bridge-trees  and  harness-work. .       9 

reinforcing,  calculating 138 

square,  framing  with  the 103 

wire  belt  lacing,  Jackson 253 

cable,  table  of 262 

Stifness  of  shafts 191 

Stitched  cotton  belting,  impregnated 

199,  246 
Stone,  broken  and  sand,  for  concrete .      71 

Stones  or  points,  station 14,  18,  25 

Stop  and  check  valves 352 

Straightening  a  shaft 219 

Straight  holes,  boring 361 

Straight  shafting  and  keyways 218 

Strain  record 153 

Strains,  analyzing  in  a  truss 146 

in  a  bolt  head,  shearing 186 

modified  by  wind  pressure 145 

Strength  of  beams 166 

bolts 185 

iron-strapped  blocks 264 

ironwork 185 

materials 163 

transverse 165 

rafters,  calculating 142 

timber,  shearing 179,  180 

wire  cable 262 

wooden  forms 84 

Stress  diagram 150 

constructing  a 152 

torsional,  in  shafts 190 

Stresses  adjusted  to  wind  pressure..   145 

limiting  unit,  table  of 174 

Studs,  Blake's  belt 252 

Sub-stations   and   stations,    arrange- 
ment of 19 

laying  out 21 

Suspended  foundations 325 

System  of  keying,  Woodruff,  the  ...   218 

Tape-line  and  pole,  use  of 50 

Taper-side  foundation,  redesigned.  .      60 


INDEX 


401 


PAGE 

Tar  and  gravel  roofs,  laying  of 156 

Targets,  permanent 14 

or  stations,  permanent 15 

Telescope,  focussing  a 49 

leveling,  home-made 46 

pipe-spectacle 49 

rifle 50 

sights  on  a  carpenter's  level.  .  .  47 

Templet,  always  use  a 325 

constructing  a 326 

setting  up 328 

Tenon,  mortise  and  "dap" 9 

Tensile  strength  tests  of  cement ....  67 

Test,  accelerated  test  for  cement 66 

for  oil 298 

glass 294 

Testing  an  engine  governor  belt ....  340 

carrying  power  of  soils 60 

cement  and  aggregates 64 

machine  for  oil 294 

oils 293 

shafts  without  the  transit 235 

sieves,  home-made 69 

specific  gravity  of  cement 69 

Threading  pipe 311 

Thrust  bearings  and  rings 225 

Tightening  pulley  bolts  and  links  .  .  330 

Timber,  breaking  strength  of 171 

crushing  journal  bearings 178 

framing 9 

trusses  for  roofs 140 

shearing  strength  of 179,  180 

sighting  and  spotting  out  of  wind  110 

squaring  around  a 108,  109 

taking  out  of  wind 110 

Tin  and  copper  roofs 158 

roofs,  repairing  leaky 1 60 

Tongs,  pipe,  use  of ; 315 

Tongued  and  grooved  flooring,  laying  1 23 

Torsional  stress  of  shafts "...  190 

Torsion  in  a  shaft 189 

Transit,  laying  oujt  foundations  with  the  14 

leveling  with  a 26 

second-hand,  cost  of 13 

test,  final  of  shafting 233 

Transmission,  belt  or  gear 377 

material,  erector's  list  of 197 

Transverse  strength  of  materials  . .  .  165 

Triangle  of  pipe  diameters 302 

Traps,  air  and  water : .  .  .  .  316 

Truss  and  roof  timbering 1 40 

Truss,  analysis 150 

analyzing  strains  in  a 145 

evolution  of  the  Howe 154 

evolution  of  the  Pratt 155 

simple,  roof 142,  143 

snow  and  wind  stress  at  joints  of  144 

Tube,  mounting  lenses  in  a 48 

Turbine  wheel  setting 376 


PAGE 

Turning  rolls  without  a  lathe 360 

Twisting  moment  of  shafts 190 

Unit  stresses,  limiting,  table  of 174 

Universal  laying-out  gage 106,  107 

Valves,  check  and  stop 353 

safety  and  steam  pipe  connec- 
tions   362 

Valves,  cutting  of 315 

regrinding  and  packing 321 

standard '205 

Vernier  scale-making  and  reading  . .     28 

Vibrations,  foundations  to  absorb  .  .  324 

Walls  and  machinery  supports 114 

brackets,  erecting 128 

for  supporting  shafting 116 

hangers  and  brackets 124 

Washers,  table  of  cast 184 

table  of  cut 182 

Water  for  fire  and  for  steam,  pumping  387 

proportion  of  for  concrete 71 

separator  and  cylinder  lubricator  341 

supply  and  pumping 387 

traps 316 

wheel  governors 379 

wheel  setting 376 

Weak  belt  joint-holes  too  large 250 

Weave,  stretch  and  weight  of  duck  247, 248 

Wheel  pits  and  canals 384 

Wheel  setting 378 

turbine  water 375 

shafts,  framing  for 381 

Whisky  jack 257 

Wind  and  snow  loads 140 

pressure,  adjustment  of  stresses 

of 145 

modifying  strains  of  in  truss  145 

stress  at  joints  of  truss 144 

Wire  belt  lacing,  steel,  Jackson's. .  253 

cable  and  snatch-block  hoist  261,  263 

strength  of 262 

table  of,  steel 262 

Wire-cloth  dam  for  alluvial  streams  385 

Wooden  factory  construction 93 

rolls,  finishing 363 

making 358 

Wood  floors  on  concrete  construction  123 

pulley, .building  on  a  flange..    .  300 

Woodruff  system  of  keying 218 

Working  fold  of  belt,  pull  on 134 

power  of  belt 132 

space  around  machines,  lark  of  12 

strength  of  blocks,  table  of.  ...  264 

Work,  repair,  bits  for 370 

Worn  bits,  repairing 374 

"Y"  or  "Wye"  level 13 

Yoke-clamp 127 


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